Sounds like a repair rather than a mod to the fuel tanks - In my opinion, rear tank mounts really do need to be cushioned/floated as they’re simply sitting on a couple of thin bits of rubber.
Rubber that sits on long tubular arms that are prone to flex just by the nature of tubing. If MMC had a rear frame of sorts, whether tubular or monococ to mount the tanks into it would be a giant leap forward.
