Been practicing this game a lot recently and wanted to try my hand at a 100% run. Since the all bosses category is shortest in-game time to activate every boss trigger, would a 100% run likewise be shortest in-game time to display a 100% on the save file?

Just wondering because from what I've been testing so far I don't think you even need to beat the final boss to get 100%? And contrary to what it sounds like, all worms and ailments on the map also don't count towards the total, it seems to be mostly the lever activations. Also showing Tommen the royal decree is 10% completion by itself lol.

I also wasn't sure about glitched or NMG either but I think I'd prefer to run it glitched. The damage boost skips are too fun and they save hella time.

oh lol, I didn't even realise that pickups didnt count towards completion if im being honest. but yeah, 100% completion on the savefile is the only way to reasonably verify a run like that. i dont imagine anyone would care to do 100% nmg, just sounds boring if im being honest lol

Ok cool, thanks. Route still needs some figuring out but I think it'll be a lot shorter than I first expected.

I've got one more question in regard to the timekeeping. It seems that the game doesn't like to update the completion percentage until after you save and quit once, meaning after the last boss is defeated you still have to spend like 3ish seconds of in game time to load back in and quit. It doesn't matter too much but if we're going by percentage on the save file it would be necessary to verify the run. So my question is whether we take the time displayed on the "the end" screen or the time displayed once the save file shows 100%.

Assuming you don't progress at all after the end screen use that timer yeah. Everything after is just for run verification purposes and won't be counted towards the final time.