It would be a good idea to add some upgrade checks to conf-sanity.sh test_32. That test is already verifying Lustre upgrades to the current version by (manually) generating images from the old Lustre version, creating a tarball of the resulting loopback MDT and OST filesystems, then mounting them and verifying the contents for each Lustre patch landing.

If the conf-sanity.sh::test_32newtarball() function is enhanced to enable quota accounting on the MDT and OST, add some quota limits, then capture the resulting quotas into the image, it would be possible to verify the quota on the upgraded system.