From what I have seen of the bike you shouldnt have that many problems as long as there is the physical space for the motor to fit.

Its always better that you dont have to shoehorn things in to tight spaces as the tighter things are the more likely something that doesnt like heat will come into contact with it.

You might consider the jackshaft kits on the market as well if there are space limitations round the back axle.

I will also say, it is not a great idea to use quick release wheels on MB's - they are not as strong as the bar axles and convenience is nothing when you lose an axle and hit the road at 30mph

good luck with the build

Jemma xx