I think this is unnecessary. IMO, it doesn't take much to make Triss's romance equal to that of Yen. Perhaps two extra scenes are enough. They don't have to overhaul the entire game for a romance. Besides, a lot of things that happened in TW2 was ignored anyway. Just ask anyone who sided with Iroveth. Same thing for TW1, ask anyone who romanced Shani. It seems like CDPR picks bits and pieces from the previous games to tell their story for the next one. It was done for all the games. Which makes me think that the games aren't meant to be taken completely as literal continuations of the last ones.
It needs three.
Act 2: Kaer Morhen
Act 2: Battle of Kaer Morhen
Act 3; Skellige
It also needs Act 3: Novigrad material expanding. That way the material is paced better. For the benefit of clarity, let me re-post the time line.
Dream Sequence/tutorial >> Prologue >> Act 1: Velen >> Triss Romance >> Act 1: Skellige >> Triss Romance >> Act 2: Ilse of Mists >> Triss Romance >> Act 3: Bald Mountain >> Triss Romance >> Triss Romance
It breaks the game up thusly:
For those who want to go the route of Yennefer, the early game introduces the character of Yennefer, a character only mentioned in previous games. The Skellige isles during the first act then flesh out her character and allows the player to establish/re-kindle a romance with her. She then figures throughout the rest of the game as the protagonist's lover.
For those who want to go the route of Triss, the events of Novigrad allow new players to be introduced to this character and old players to re-kindle their love interest of choice from the previous games. Early act two, i.e. prior to The Isle of mists, Triss should have extended content that allows her to be fleshed out for new players and old players to feel that she's being treated with equal respect to Yennefer. Act three should consist of extended content to allow all players who choose this romance, to feel that she's an important part of Geralt's life.
The issue with the romance is that the is insufficient content to make her attractive to newcomers and makes veterans of the series feel let down but just slapping in scenes or dialogue her or there isn't going to work because the pacing of the game is all wrong for Triss so by extending the content and pacing it the final two acts, neither romance ever goes more than a few of hours of gameplay without that romance choice figuring in Geralt's life.