InRangeTV mechanically zeroed a Glock equipped with a Delta Point Pro using a Ransom Rest.

I have been considering doing the same with a Glock equipped with an RMR.  Is this a wise thing or are there negatives to it?

YouTube Video Link:  

Still not the same as holding it in your hand.

Keep in mind that the gun starts to recoil as soon as the bullet starts moving in the barrel.

Especially in handguns.

It is why many handgun sights are set to depress the barrel slightly.
By the time the bullet exits the gun will have recoiled in your hand.

I shoot the pistol off hand, so I sight it in while shooting it off hand.

The only reason I've every rested a handgun is just to see how good it will really do for 8 or 10 shots.  A way of knowing if that occasional wild shot out of the group is me, or the pistol.

Mechanically zeroing the optic would be a good reference / starting point, but I would stress it is very important to finish zeroing the optic freehand as you would normally be shooting it. The way a firearm shoots fully supported vs. free hand can vary, no reason not to confirm your zero after you mechanically zero it if for nothing else but peace of mind.

It’s neither good nor bad.  It just...is.  There’s no reason to not do it.  Obviously you want confirm everything in-hand to ensure you are getting a zero away from the rest.  That being said, zeroing at 10yds is not difficult, and I would argue that if you need a mechanical rest to zero at 10yds, you have other issues that need to be addressed.  Using a rest for 25yd zero would obviously be more feasible, but given what we know about ballistics, the 25yd zero really doesn’t offer any advantage over 10yd.
If you have a rest, go ahead and use it.  I wouldn’t go out and buy one just for the purpose of zeroing a pistol RDS though. It’s more of a convenience than anything.

So if I consistently shoot right should I drift my sites or get better technique?

You need an experienced trainer to watch your handling
and help you figure out if it is 'manual of arms' or the sights.

Do you consistently shoot right with most/all pistols regardless of sights, RDS, zero technique the its likely you. If you shoot dead on with every other pistol and just that one pistol shoots right then you drift your sights