I've hooked up those 2 flat metal slotted strips built to connect the rack into the seatstays to the plastic collar that was used to hold the crappy rear reflector to the seatpost. At first, I thought this might not be a good idea, because the reflector collar might not hold up.

But after 2 untility bikes have been in heavy use with the rack tied into the seatpost via the plastic reflector collar with no breakdowns over 3 years--- well, I'd do it again any time!

Has anyone else done this mickey mouse reflector tie in and did it ever fail?

A a general rule, the smaller the frame, the tougher the rack is to fit close to level.