This is very very light cheat, that may gacha games have this "feature".
Never will they ban anyone for this as It is just suspend and resume feature.
IF you want to dig deeper into cheating, you will find some ridiculous one.
It's fine. I don't think the GUMI police will be losing much sleep over it.
Didn't they actually banned users in JP for this? But it was enchanted maze, not trial.