Self-Inserting is a kinda hard thing to do in this game.
A.) Everyone has their own visions of how their version of Steele would react to events that happen in the game, however the writing sometimes goes against their headcanon of that for there are writers that write dialogue for the MC and whatnot, so the writing will go against how people imaging their variant of the PC. And B.) Literal Self-Inserting yourself into the game, or loosely basing the PC off the player, which some indeed have done, is almost next to impossible because the thing's STEELE is written to say will not sound like something YOU would say when this or that happens.
I've tried both of these before, and gave up on self-inserting kinda. Because some of the stuff Steele Jr. in the game says is not what I MYSELF see my version of Jr. saying, I like to imagine the dialogue and how events with him play out in my head... and there are most certainly lines in the game I do not see myself saying as well to do the second point even in the TiTSverse. This is kinda strengthened when I see writing with so much direct dialogue written the PC in scenes. I mean yeah, while there are times that I instead image a different set of dialogue here or there as opposed to the static lines in the game given to correspond to how my version of Steele is, and how I imagine he acts to this or that, it still kinda ruined the immersion for me at times, especially with the 'dialogue being written for the MC' bit if I feel it's overdone in a scene.
Kinda hard to strike a balance in that regard in writing tho. Too much dialogue written for the PC can break immersion a shit ton for people, yet if the writer doesn't write any at all, you risk the chance of people calling the PC 'boring' in your writing.
When I'm not having the game do it for me, I like to imaging the PC saying something different to what the game writes out.