I didn't check yet but I'll try to find a way for you to search, I also play all renpy games with URM. Brb with good news for you I hope.
Herates I think I found a way to search the variables of the scenes in the gallery (untested), not sure if AtemX spelled it wrong to make it harder for us haha but search "Galery" I'll attach a screenshot bellow from my save at the end of episode 1, still didn't started playing the update.
View attachment 4993908
Edit: Just tested it and won't work without a variable get defined first (will give a non defined error), probably will only work once you get right after the scene where the variable is defined. Not sure if you understand what I'm saying, simply if you finish the update almost sure you can unlock by this method even if you didn't unlock them while playing.
For example at the save at the end of episode 1 I can change the "galery" variable of all the scenes from episode 1, I can lock them and then unlock at will because the variable that is called is already defined, but because I still didn't played the episode 2 when I try to unlock episode 2 scenes always give a undefined error.