You can do it with save edits, but there's not much point. CG's are tied to both beds and affection level. So you could manipulate affection levels to try and get NTR/Hopeless/True of two characters in one run but you have to do it from the start with no rests so you can manipulate all of that with one save all the way near the end. Not to mention you still have to finish the run. Just save yourself the time and use gallery saves.
[Shima CG's have to be done on individual playthroughs, most likely]
If you *still* want to do it, you can use
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. Make sure you have more than one rest, save in the break room and then upload that save. Use a rest, save ( in another slot) and then upload that save over the you did before. It should show a variable that went down from your original run. Change it, download the save and use that.