Some 3/4 and 2in conduit hanger bolted together with a locknut. 1 1/2in would work better for the Q8’s size. Old bike inner tube used to not mar the bike frame or light. Would recommend a hanging or sideways orientation so you don’t throw off the center of balance. I can’t say that I notice it the way it is. If you’re trying to ride offroad I’d recommend putting something together using Truss Clamps.

Here it is with the MF01 mounted below and C8.2 on top.(only the MF01 is on)