So did the interior of the T-wing, hence them dropping from it's artificial gravity. Or does something that simple need to be explained nearly a year later?
Using the artificial gravity of a ship to drop bombs would be a
horrible way: Because the center of gravity would be somewhat close beneath the "floor" of the ship, which means all bombs would drop into space and fall back to the gravity generator on their own ship, and land on the underside of the ship dropping them.
I always assumed that the TIE-bombers in "Empire Strikes back" simply had their ejection tubes faced downwards - that would make sense for, you know,
a bomber. There is really nothing in ESB that supports the bombs were just "dropped" (like in Last Jedi), but that they were simply
shot downwards, they were even glowing!
Finally, an asteroid is orders of magnitude bigger than a starship, and - this is important - made
of dense mass. That generates a gravity field (though not enough for Earth-like bomb dropping). A starship is hollow, the only real mass are the walls and engines.
Also: I really don't care about realism in Star Wars. That bombing scene in the beginning is one of the few parts of the movie I really liked. The problem with the slow-chase speed wasn't the science behind it - it was that it was
fucking boring - and that Finn and Rose simply could have used their hyperspace-capable ship to evacuate the 300+ people 50 people at a time to the Casino planed, and that the Empire suddenly forgot it had TIE-fighters that are faster than capital ships and could have blown the ship to pieces.
Set it in the Kelvinverse if you have to (no reason not to keep the possibility of those two projects alive), but spin a yarn about a different starship and crew. After all, Beyond ended on an open note. The Enterprise-A is still out there, somewhere, ready for future movies. 
