Default. Graces sections are made with FPV in mind imo, because:
1. When the game is running with the RT set to On with the PS5, the game drops frames in some parts of Grace's campaign when you use TPP instead of FPV. Examples: the waiting room with benches in the hospital, some parts of the basement, probably more but I went back to FPP after the 2nd time it dropped frames. Probably because its also rendering her whole model on top of the scene.
2. The TPP switches shoulders basically never, its always on the right side and theres parts where your hiding spot is on your right so you can't see around the corner/hiding spot properly without exposing yourself. Example: the basement when you first take the electric plugs and the girl turns up, you must hide there and wait and the open jail cell is on the right. You can hide further back on the left but it seems like a terrible idea without prior knowledge that she'll turn and leave scriptedly.
3. The game has added falling animations to slow you down in TPP, vs just slower speed in FPP, which imo is more frustrating than just the tension of constantly slower movement.
Regarding no. 1: Maybe the patch changed things and it didn't stutter on launch/1.00 with TPP in those spots, I only did TPP on my 2nd playthrough after patches. Still if they had TPP equally in mind as FPP for Grace you'd think the stuttering would be present in both modes after patch.
So the game is absolutely perfectly fine with TPP for Grace and the above are minor things in the grand scheme, I just think overall the game is more enjoyable when you don't have an interruption to your disbelief being suspended by a camera or stuttering when 95% of the rest of the game doesn't have those issues.