That's true, cover rollers will, in time, rip the frame off the tub. I have a 5-person square framed multi-jet tub in my garden and I've got premium style hot tub covers for it. I thought of having the rollers attached to the frame, but from what I saw in-person, I slightly renewed the design. I had an extra 90 degree angled triangle frame fixed to the ground to support the weight of the tub attached roller. Even if the roller gets heavy, as the cover gets heavier in time, the weight won't be on the tub frame, instead that weight will be handled by the frame attached to the ground.