At end of Blood and Wine Mainquests you can earn over extra 1000xp with a trick. Thats a half LVL update!
(Its primary ment for players who determined to check Syanna and NOT to see Orianna at all, like me was)

1. In "Night of Long Fangs" (& before) be friendly to Damien, calm him to return with wounded soldiers to barracks and choose to see Syanna playroom,
at 2nd floor ABORT at 3rd step of new Mainquest "Behind Hill and Dale" and DONT examine red book behind the locked door! or all below is impossible.
2. Go out restart quest "Night of Long Fangs" choose "ask Orianna" walk southeast to meet her at the waterpool area where the artist party with Anrietta was then
3. Start and complete new easy quest " Blood Simple" with over extra 1000Xp ( which would be skipped if you examined the talesbook in 1.) at the end choose "meet Regis at Docks"
4. SAVE before goto Docks. NOW you can CHOOSE 2 Ways to continue.
a) you can again finish Syanna Quest (after which you still have Oriannas key to Unseend One cave to visit later to get TWO pieces of upgraded Vampire Lv53 set sword+glows, after the water dive at entry)
This Syanna Quest "Behind Hill and Dale" leads to VERY amazing locations and the "good ending".

b) OR finish Orianna quest to get complete epic Lv53 red vampire Armorset, compatible with black mask!)
and visit Unseen One "twice"(u will see:) dont talk too much to him, keep dialogs short.

c) both a or b paths lead to same next Detlaff main mission.

You can kill lots of other vampires while explore the chaos in whole city to gain XP. Strong 5 vamp group at southern Lebioda Gate cementary coast + bands of looters + tough Garkin Quintett near sealedoff "Nilfgard Ambassy" plaza,
approch from water, empty nearby Phasanery is accessible from upper Balcony door and new house corner doors .

When you start "Blood Simple" few portals work again, map area is restricted, you cant Meditate, BUT you can go to your Winery Home down to the Alchemy room, at the bench you
can refill potions + enhance to 5 bombs and sharpen Swords and Armour too.
Funny is even one dye merchant at southern port still buys swords in the chaos!

Hope CDPR will not "fix this" before they patch the 7 year old "Winewars Belgaard" Quest bug with the Endrega nest.

Its just always worth to make a break in a chaotic mission where you are in hurry. Explore to find ununsal ways and locations. This trick should work on PC and Consoles, no command or mod needed. Done on 4.02 PC.

Im Lv55 with ALL sidequests, HeartStone and Questionmarks finished (NO gwint at all) in mainquest have to do after BloodWine "Find Ciri at Myst island", money 200k not NG+ no Mods, my toxic BearBuild with Euphoria mutagens was inspired by Gametasy/YT:FragNart *Danke*

*GTX1660ti*1150 Z87 Board*XeonV3 1246 3,5Ghz Quad (aka i7-4771)*24GB DDR³*1TB SSD,*FHD 24"* plays still fine!

Neither a bonus, nor a bug nor something new. This has been in Blood & Wine from the beginning.
You might actually be forced to talk to Damien before going to Orianna, as Damien might become unavailable.

in step 1. i examined the book and was teleported straight to the Tale world = NO More Orianna im afraid.. thats why "Night of Fangs" Quest says Ask Orianna OR find the Talebook, in my description you can do both imo, After enter Taleworld path in 1.) Mainquest "Night of Fangs" is succesfully CLOSED.

The choice made during 'Night of Long Fangs' influences the ending of Blood and Wine.
You can choose between going to the fabled land or going to see the unseen elder.
If you read the book, you chose the fabled lands.
However before getting there, you have the option to go to Damien or Orianna.
Once you visited Damien first you still have the option to go visit Orianna.
When you visited Orianna first, you can't go to Damien anymore. However when you talk to Regis, he'll tell you he talked to Damien and knows where Syanna is.
If you have spoken to both Damien and Orianna and did Orianna's quest, you have 2 choices when speaking to Regis:
- go to the playroom, read the book and go the the fabled lands
- go see the unseen elder
Obviously if you didn't visit Orianna but go straight for Syanna after talking to Damien, you'll miss out on Orianna's quest and on actively choosing an ending.
This has been in Blood and Wine from the beginning.

Thanks your your detailed description. Im NEW to Witcher 3 started as NextGen4 on PC after i finished awesome Cyberpunk77. This MainQuest part has many choices is a bit complicated and the Chaos in the city puts you under pressure and hurry.

didnt wanna go thru burning city filled with monsters looters and barricades all way back to Orianna, did "Lets check Syanna, its nearby" imo some new W3 Players could feel similar and would unnecessary miss great & easy Orianna quest "Blood Simple" after which u stil can go Syanna way. if you aborted search Syanna playroom at the last step, Regis dock dialog will be " please lets search Syanna, we were almost there"

"Night of Long Fangs" objective "Find talebook" OR "Ask Orianna" suggests to choose ONE of the two, while u can do Both with some extra XP points AND even 2 new Red vampire Armorset parts (Glove+strong Steel sword) which work together with the weaker similar Mushnem Black vampire set, even if you Dont wanna do the "Unseen Elder" mission.

Just use Oriannas Key to Unseen Cave (even just BEFORE meet Regis at docks!! theres a boot and cave is straight all way south from this dock, near the AARD Point of Power portal) and pickup both Red Lv53 vamp parts at cave underwater entry. IF you go further, Unseen will teach you a lesson :) Then just take ship straight north, meed Regis and you can goto FairyLand.

I was aware of the option to go into the cave and get the gloves and sword.

Play the entire game at least once, then look for guides, secrets, etc.
Fandom is a good source, so is VG247. You can also get a quite extensive check list at Nexus Mods.