After spending so many hours deciding between the two options, and after some emails with Jazz, I just bit the bullet and decided with dual drive. The main points in my decision were:

with AM882 there wasn't any issue with the gantry racking from one motor stalling as they have stall detection alarms, and the machine will E-stop before any damage is done.

Next, as for sync issues creeping in, Jazz says with descent drives this is drastically reduced compared to cheap Chinese drives. Obviously with one motor and belt its completely eliminated and is only a problem on very long jobs, which I doubt I'll be doing. Though you never know.

Then with 2 motors tucked away in the corners, it keeps the far end of my router free from belts and motors and tensioning arrangements, allowing for sliding long materials through.

With the long belt and one motor, I reckon a larger motor like a nema 34 would have been needed, and since I prematurely bought a nema 23, thought I'd use it on one side and buy another 23.

Also I think the 23 motor can spin faster at the top end, which will be ideal for my incorrectly ordered 5mm pitch screws, when traversing.

This is how I came to my choice, but it no big deal if I want to change change later. And I'm sure someone here will snap up my spare driver and motor, lol

Adil