Hi @guruprasad apologize for the delay, and thanks @kyrofa for your feedback, its very nice to “read” you around :).
As @kyrofa mentioned, we have a process to grant classic and the snaps that are granted such confinement should belong to one of the supported categories. In this case, I believe we still need more information to proceed.
Have you tried plugging the-block-devices-interface (as per the iface code it should allow you access to the raw devices https://github.com/snapcore/snapd/blob/master/interfaces/builtin/block_devices.go#L61), the-scsi-generic-interface and others related from the supported interfaces ? I suggest you experiment with those, use snappy-debug (that will suggest interfaces based on your snap behavior) and see if glucometerutils can stay under strict confinement. If you still see issues, free to come back here and share the denials in case we can keep exploring alternatives.