Pretty interesting, especially the price!
I'd like to see details of the coupling system.
Notice that the lower part, an inverted T, must go between your feet. On my Ti chairs, I'd have to cut and weld that part to come down at a more acute angle, in front of footplate, then extend horizontally. I expect that the lateral tube must socket in a pair of pillows when it picks up the front of the chair; otherwise there's no lateral connection to the power wheel and it would not stay in place, so I'd need to fix something under the foot plate.
Somebody ought to invest ~$500 in one of these and get back to us

and if the coast is clear, I'd get one!
EDIT: I followed this link below the video:
https://www.alibaba.com/product-deta....71a8bdeZHFeIT
The attachment and the device on this site don't match the attachment or device in the video, but they are very similar.
If I could get the device on the site with the coupler in the video for $500 and it was reliable and powerful enough for hills, I'd be a customer.
I'd like to know the weight but couldn't find it.