I am in the process of adding e-assist to my RotoVelo velomobile. Yesterday I was getting bolts and the like to attach the controller.
I decided not to go with mid-drive because I want to be able to use regen. I think this will be heavy enough for that to be useful. I have a 48V 20AH battery I will be using. Keeping that to about 20mh, I expect to see 75-100 mi range, depending on how much I put in.