Hello GOG Staff, as you know, one of the oldest and most annoying parts of the GOG store front is the fact that various Lesser Editions do not get marked as owned, despite us owning Higher Editions, or that various Bundles do not get marked as owned, despite us owning all contents within.

Now I understand that this is a complex and nuanced issue. There are games like ENCODYA, which do not have a "Deluxe Upgrade" DLC and so we do not want people, who have bought the Standard Edition, to be locked out of buying the Deluxe Edition later on, in order to override the previously-purchased Standard Edition. That is actually a big problem on Steam with this game. If we buy the Standard edition on Steam, both editions get marked as owned and we cannot upgrade, without refunding the Standard Edition.
Relevant Attachment: Image 01.png

So in this specific case, GOG's ownership label problem becomes a benefit. These cases are rare though. In most cases this issue achieves nothing, other than to make "Hide owned products" filter less effective.

At the same time I understand that sorting this problem would be a big undertaking and that there are risks, that trying to tackle this problem may create many unforeseen consequences.

That being said, we also know that the Checkout Page is aware of our ownerships properly and warns us whenever we are about to rebuy owned content.
Relevant Attachment: Image 02.png

With this in mind, I propose a "middle ground" solution. Don't mark affected items as owned, don't prevent us from re-buying them either. Keep the checkout warning, but introduce new Label(s) as a form of shortened checkout warning on the store front.

This new Label or Labels could be "Partially-Owned" and / or "Owned Indirectly", or something similar. I'll leave the exact wording for you and your marketing team to figure out. It could look something like this. What do you think?
Relevant Attachments: GOG - Partially-Owned Concept.png and GOG - Owned Indirectly Concept.png

With this/these Label(s) in place, you could create a new filter called "Hide Partially-Owned products" or "Hide Indirectly-Owned products". This new filter should be independent from the existing "Hide owned products", which would allow us to mix and match them, thus greatly improving our shopping experience.

Seems fair and logical to me. I'd support this.

Would be a nice idea, doable, but a bit heavy on the server, if done in real time.
The server has to check all products contained in the shown bundle/deluxe edition or check all bundles/editions if they contain that product.
For a page with 30 banners or more that's a lot of server load.
But if it was done once in a while (whenever a new product is added or bought) and the result was cached, that would work.

For GOG to do anything like what has been suggested, would likely be no easier than just marking games properly in the first place. Clearly when you go to the cart, some kind of lookup is consulted. At the moment there seems to be a different lookup when just viewing games or a sales page. That is what needs to be corrected. Alas, Hell may freeze over before that happens.

Meanwhile we can kind of help ourselves somewhat.

I have a few purchases, I already own in some manner at GOG, hidden from me by filters. These are not GOG provided filters but filters in uBlock Origin. I could do many more, but haven't bothered so far. There is a topic here written about such filters, with examples, by one of our members. They used it for some of the spam threads we get, and other things like porn etc. You also don't have to use uBlock Origin as there is another script alternative with something like GreaseMonkey etc.

The key to these filters, is making them unique enough, so that only what you want hidden, is actually hidden.

Well they already do at least two checks for every single page. 30 or 48 items, they all get checked for "traditional" ownership and whether or not they are wish listed. This would simply be a 3rd check. They could also add a rule that said do this 3rd check only if the other the "traditional" ownership check found no results. In that case I cannot imagine this adding more than 50% extra work for each page.

With the exception of the Encodya problem that I've mentioned in my original Post, Steam handles all of this a lot more gracefully. Please see the attachment. Yes it is indeed a different lookup on the store front than in our checkout page. If I had to guess, the store front looks up our order history, while the checkout page looks up our library. The order history page and our library are not the same thing and so the problem gets created. Order history will list the name of the edition or a bundle, while libraries will not. Libraries only show games themselves, regardless of how they were acquired.

Of course we cannot just lazily change from looking up order history to look up library, because that may prevent us from upgrading games like ENCODYA and we do not want that either.

So my proposal is to look up both and use different tags for both. Order history still takes priority, but the library gets noted too. Library would get checked literally the same way that the checkout page does, only in the form of a new label while on the store front.

I've just added 4 more filters to the Dashboard in uBlock Origin.

gog.com##product-tile:has(.product-tile__title[title="The Witcher 3: Wild Hunt"])
gog.com##product-tile:has(.product-tile__title[title="The Witcher 3: Wild Hunt - Expansion Pass"])
gog.com##product-tile:has(.product-tile__title[title="The Witcher 3: Wild Hunt - Blood and Wine"])
gog.com##product-tile:has(.product-tile__title[title="The Witcher 3: Wild Hunt - Hearts of Stone"])

I own the The Witcher 3: Wild Hunt - Complete Edition
It shows as owned, but those four game entries don't show as owned by me until I get to the cart.

Here's the query to use if you want to test it out for yourself.

Search query for The Witcher games

The screenshot attachment is what I now see for Witcher games with that query.
Prior to my filter additions I also saw that basic game and 3 dlc entries, which were not listed as in my library.

A "owned" or "wishlisted" check is easy, they only have to do a simple "exists" query in our library or on the wishlist.to go through our library. But a check if we own all components of something actually requires to look into that something and see what it contains. Especially the 'partially owned' thing is costly.

Of course it's still doable. But as I said, it would not be necessary to perform it at every site call.
If you buy a game, all bundles containing it can be marked as at least partially ownedWhen you refund it or buy DLCs or another part of the bundle, the check is done again. When they introduce or change a bundle, the check is performed for all users. The rest of the time, the cached value is used, there's no need to perform the check more often.

But all of this would requite someone at GOG actually seeing the need for it :)

The "solution" in the OP seems to do nothing to solve GOG's massive problem of having no fair upgrade path for many games, like Dying Light 1 for example, of which the purchasers of the "original" version that was initially released on GOG received a raw deal, and they became massively ripped off relative to later customers who were able to purchase the much more complete "Definitive Edition" of the same game, and for a much lower & more fair price than the original customers can, since GOG offers their original customers of that game no fair upgrade path from the "Enhanced" to the "Definitive" Edition.

Therefore, since the "solution" in the OP is ignoring this massive problem, even though all of these issues I've mentioned are related to what the OP is talking about, I think it is a bad solution in the OP, and IMO it needs to go back to the drawing board, until if & when such time comes when it includes a solution to the problem that I've just described.

You're describing a different problem. You're talking about upgrade paths, I'm talking about ownership labels. Complain to the publisher. Outer Worlds remaster had a massive discount for the original owners on GOG too. If Publisher cares, there is a way to provide an upgrade path on GOG too. The problem is that most do not, but I am not talking about that topic. They still need to do something. Every other time a bundle comes out, I see people complaining about said bundle not being marked as owned, despite people owning everything within. Again it's not really an issue on Steam. And that's something I pondered for a while. it is probably in their best interest to keep this broken for a whole. It allows whales with OCD to rebuy games for no reason other than to gain a pointless label.