with little extras, such as new items, Steam achievements or even a new difficulty mode, more challenging than the Tactician mode.
All those would be nice, especially harder difficulty mode that I heard many requests for. Not sure why we would need Game+ for it.
I can’t quite imagine what you want from game plus, in spite of game somehow giving you special rewards for replaying it - I would hope that the alleged “no two playthroughs are the same” would already provide enough of an incentive.
That said, I am not a New Game+ player. Never seen a point of it.
I think you missed the point of NG+. I would say that at least half of my 2 play-through's have been dedicated to finding loot, finding camp supplies, opening up all 10,000 containers in the game for rotten food (or nothing), and
managing inventory. A NG+ normally starts you with everything you finished the previous game with (minus items that are specifically achieved via a quest) so that you may replay the game at a harder setting (since you are full flex at level 12) and enjoy the multiple story lines and potential endings. Basically it allows you to focus on the game, quests, missions, companion stories, etc without all the mundane time-sink management as I listed just before.