Just a heads up GOG Admins your policy won't fly as it stands in Australia; I'm not being a i think i know better than you guy.
I actually know that another online distributor is currently being taking to court by the A.C.C.C (our consumer watchdog) over misleading and hence fraudulent terms considering refunds.
In particular what stops your policy from being legal in Australia by Australian consumer law is:
8. What if I don't want to bother with trying to get my game working? All I want is my money back!
Our top priority is to help you get the game working, and this means that we will require some cooperation from you. We won't ask anything extravagant, or super time-consuming, like a system reinstall, but if you absolutely refuse to try anything, we won't be able to determine whether the problem can be fixed or not, and won't be able to issue a refund.
This is especially relevant if there are some glaring issues with your computer, like DirectX faults, or drivers that are ancient, or even missing.
The current court case against Steam, is obviously more blatant in their disregard for the laws of our sovereign nation in regards to consumer returns policy, but none the less if you sell to Australia you sell IN Australia.
Australia's return policy does not stipulate that we must try every measure of yours, nor allow continued testing on your own 'lab conditions' to assess whether or not 'we' are allowed to return an item or product; only that for us it was not 'fit for purpose'.
I refer you to the publicized case of ACCC vs Valve (
https://www.accc.gov.au/media-release/full-steam-ahead-accc-institutes-proceedings-against-valve-for-making-alleged-misleading-consumer-guarantee-representations)
I point you in the direction of the mid third paragraph...
Valve made false or misleading representations to Australian customers in that they were "not under any obligation to repair, replace or provide a refund for a game where the consumer had not contacted and attempted to resolve the problem with the computer game developer".
I don't like being that guy, but your leaving yourself open to litigation and our Government has deep pockets & a long history as the worlds foremost developed nanny state.