I use a Classicboy App that uses VBA-M to play GB, & GBC games. I also own this physical as well, i have yet to notice a difference between the two. I just wanted to know why this emulator was banned

Hi, unfortunately VBA-M is not accurate enough (it runs too fast), so it is not allowed here and in most GB games. Also, currently there is no mobile emulator which would be accurate enough to allow for speedrunning.

If you are interested in the numbers, please have a look here: https://www.kleemans.ch/static/gb-emulator-timing/