naw let me put it this way. you do NOT want to have two systems a hub and mid drive system on one bike, especially not on a single speed. it sounds like that bike has integrated motor controller and battery already, so adding a whole new system would NOT be worth it or practical in any way. further a mid drive conversion is ideal for 7-11 speed mtb hardtail frames generally with few exceptions. youd want to put a mid drive kit on an ideal bike frame that suits you and your use case. do u need steep climbing, hills mtns and forests? or flatter easier terrain for commuting. your setup depends on that.

example. I use a 10 speed rear cassette 11-36t with a BBSHD motor 42t lekkie front chainring on a mtb frame search my Victory post in the forum if youd like to see. my area is mountainous, steep etc, some 45 degree inclines - very challenging to bike up. my drivetrain setup is the ideal sweet spot for climbing steep hills while also allowing good top gear speed, 50-60 kph (32-37 mph) on flat ground w just the motor. with just the throttle yes i can pop wheelies easy, it even can get annoying because it happens too easily (mostly going uphill) as the throttle is quite strong depending on how you program the controller.

hope thats clarifies. not every bike is suitable or practical for a mid drive conversion. mostly mtbs.

honestly I doubt it. but maybe u can be the first. we suggest avoiding hub motors altogether, mid drives have more torque and power. u only need 1 mid drive motor to climb anything if u want. whats your rear cassette gear ratios? 42t front chainring on the motor helps with steep climbing. usually rear is something like 11-36 tooth gears. great for climbing. going with two batteries, two motors, two displays and throttles, two sets of cables is likely way more convoluted than its worth. syncing the two systems while riding? i dont see how thats feasible or the point of it. one good mid drive ebike kit is all u need.