So I do OMAD 4x/week and do 20/4 the other 3 days. In my experience and opinion there’s absolutely nothing wrong with doing so and makes OMAD easier when you have a few days with greater leniency to look forward to.
It’s absolutely OK to mix up your schedule on different days of the week. If you’ve had success with 16:8 in the past, then OMAD will likely speed up weight loss a bit by comparison — less time to eat can mean eating less overall. If you tried OMAD one day and felt good, then it might work well for you! Give it a try and see how it goes!
It seems like IF has different effects on mental health for different people. Some feel much better. Some feel worse. Some (like me) don’t notice much change either way; I still have bad and good mental-health days at about the same rate as before I started OMAD. It’s one of those things where you just have to listen to your body and see how it affects you.
OMAD has helped stabilize my blood sugar, though. I used to get bad non-diabetic reactive hypoglycemia — blood sugar crash four hours after eating, every time. No more — it seems totally gone. Because of that, I feel so much better day to day.