Interesting build, do you have any photos of that rubber you used?
I mean its bulky & heavy & not very stealth or streamline. Unlike my BBso2 there will be no mistaking that this is a motor, I'll have to be careful at my regular riding spots and not get caught.
You can't compare this kit to the BBS02, as the BBS02 is only rated to 750w continuous and 1600w peak, these AFT kits are rated at 1680w continuous and 2800w peak. So of course the BBS02 will be a lot smaller as its half as capable so you would expect half the size and weight . Lucky you didn't buy a GNG kit as they are even bigger and even more bulkier for the same power as they don't have the compact planetary gearbox and the controller is bigger.
Probably the best way to make it more stealthy is to paint all the silver parts black to match your bike?
Can aluminium chain rings you want to change to , handle the 2.8kw power ? I think that's why most people use steel rings on the high power builds.