You could use RTA (Real time with loads) and LRT (Real time without loads) and retime runs like that

it's totally possible to write a small script that tells livesplit to stop the timer during loading, I did it once and I have zero experience in programming, i don't remember much about it but basically you use cheat engine to look at the game data and you either find a variable that always changes when the game is loading or a variable that keeps track of in game time (some games actually have a timer in their variables even if they never display it to the player) - you need to google "livesplit load remover" and probably look up a couple cheat engine tutorials as well as you do need to learn how cheat engine works in order to find a memory space that is used by the game consistently or else your script might only end up working on your computer but not on another device

hope this makes sense as I am not very knowledgeable in the matter, you could also go ask for help on the Speedrun Tool Development discord at : https://discord.gg/BB7s7Kvk I would still recommend doing a bit of research on your own before asking