hey @om26er, have you tried staying under strict confinement while plugging some interfaces that could grant accesses to the locations needed by the snap? As per the process for reviewing classic confinement, access to arbitrary files on the system is not typically a justification for granting classic.
I believe if you plug interfaces like block-devices, personal-files, system-files, home and even removable-media desync should work unless it requires some specific accesses not provided by the existing interfaces. I suggest using snappy-debug to detect any other interface needed.
Thanks!