Skip flags that are saved on a soft reset: 0001 - 0063. Apparently.
Normal flags saved on a soft reset: 0064 to 7999, apparently.
So the new game's first event should probably use SK- to unset the skipflag.
Theory... the save points should have an H/V trigger in line with where the player is when saving... which sets a flag (and mentions costume unlocked) IF the skip flag was set... and said H/V trigger vanishes thereafter. For good.
Worth a try?
Thank you so much. It now works much, much better now. I'll now go and apply this to the Taboo Zone's bosses once I'm done redesigning that place.