Your diet sounds fine. TPG is a complete diet so i’m not sure what supplements (vitamins) you are using but you don’t need any. Just TPG and f/v every night. I would cut back on the yogurt drops as they are not as healthy as f/v. One a day is probably fine. Mealworms can be given 3 a week and they LOVE them (but they are high in fat so be careful).
Drooling over their favorite food is a normal response.
Not eating a f/v they used to love is normal. They switch their preference often. Mine LOVED apple and then didn’t eat it for over a year and now will eat it again.
It sounds like you are doing great! :)