Update by next week hopefully : )
I did alot of testing and came up with many grab release's for Bowser, I in no way, copied grab release stuff from other threads, that being said. I'm still adding data, but I have alot of info right now. Characters like Metaknight and Olimar cannot ground escape from Bowser's grabs, they can only jump escape his grabs, however, if Bowser is grab jabbing the opponent and they try to escape as they're getting hit by jabs then they will ground escape from his grab. This applies for ALL characters.
Jump Grab Release: When a character breaks out of a grab jumping.
Ground Grab Release: When a character breaks out of a grab on the ground.
Allisbrawl
[Jump Grab Release]
* means a character can only jump escape.
Kirby *
Grab release fair
[Ground Grab Release]
** means the character has to mash out as your grabbing jabbing them in order to ground release
Kirby**
Grab release regrab
Grab release overb
Grab release ftilt
Grab release jab