I think I'll start off by saying that while I haven't touched the game in 2022, I'm running under the impression that the save system hasn't changed drastically during this break. So here goes:
I'd say the general risks come down to how familiar you are poking around in things with Regedit. If you've never had to open it before, this is probably not the best situation to learn the inner workings. If you already know your way around it then you can effectively use it like Cheat Engine while the game's opened, as I usually do since I ain't got the patience to wait for them clones to bake properly (disclaimer time, I do run this on Linux via Wine, so there's a lot less risk on my end.)
As for the entries themselves, while it's certainly not ideal for a game to save its progress in the bloody registry of all places, the bright side to it is that the entries are mainly all the flags being kept track of by the game and the names are English-enough that you can work out what does what (think of how a Renpy save looks like if you open it on Saveeditonline.)
That all said, by the sounds of it one of Talia's flags needs a little nudge of +1 to keep your game moving. Can't say more for sure right now since I'm still downloadin'.