Yes; as long as you have to have saves prior to the event trigger, edit Futaba’s lust level and yumiknows flag will do the trick (but once you missed it’ll just be missed I think)
I'm pretty sure you can add scenes as being seen after the fact with the URM but it's a headache if you can, you have to go into the script files and find the relevant section and then lay down the things it sets as set in the URM (something like scene41=true) but the way i fixed my save after missing baby finches was to go to the relevant script file, look through it for the scene where the scene was set to 'seen' or 'true' or whatever it was and simply add in the line (or two? i forget) into the script
after a scene i was up to. After saving and reload the game i ran past the section i edited and the scene became replayable in the replay menu, i then saved and reloaded after editing my edits back out and continued on my way. I was desperate and it was tedious but it's doable if you're determined. Far FAR easier to just reload a save from before and use the URM, and also, another good reason to have the URM is you get little pop-ups in the left hand corner when a path check is flagged and by reading it you can determine if you pass or fail it and whether
you are ok with the outcome or not... basically a big warning:
"is Miku lust >40"
"true=scene41"
"false=endscene"
Same for flags, you really can't get fucked by Selly if you have it on... again, for anyone new who's reading this, if you want to control the game and defend against Selly being a dickhead, get the URM.