I was testing/running 100% earlier and after I died once, I noticed I somehow unlocked Dio's Best Friend, even though you need to die 50 times. Is this some kind of glitch in verson 1.2.2? Or do you need to remove another file other than Save.ini when starting 100%?
Here's some screenshots:
Just checked both my versions of RoR (steam and speedrun), neither save_backup.ini anymore. Might have been removed when Steam Cloud got added. Maybe there's a temp file or something outside of where I have it installed, but I haven't had any luck finding it yet.
Edit: Just re-watched the vod and it was indeed on my first death. Also just tried replicating it and so far haven't been able to. Seems to just be a lucky glitch.
It sounds like it does save your death counter somewhere. But I wouldn't know where to look for it. I don't think it's reasonable to expect a full game wipe and reinstall for every 100% attempt, so if you get any useful remnants after deleting your save.ini, feel free to abuse them :P