Hey xxx, the answer to this one is very individual and depends a lot on what you are comfortable with, lots of players have different grips and sometimes different grips on certain shots. To be honest it’s just how you personally feel comfortable, some shots like the backhand block you may find easier to have the thumb higher or the index finder higher for flicks as you said but overall I think if you can keep a consistent grip its more balanced and you don’t have to over think then.
So experiment to see what feels comfortable with you but the different grips won’t hold you back from improving, find what is comfortable for you and stick to it 🙂
