Disc quality tests for MDisc media?
 

When long-term storage (many years) M-Discs DVD burned in 4x before is it necessary and mandatory to do a "Disc Quality" test before storing? normally i just read test nero disc speed or imgburn option verify without the Disc Quality test the data is unreliable?

Required? None.
Smart to do? Yes, use Nero CD/DVD Speed, or alternative. Surface scans, jitter, PIE/PIF.

Failing a test, or jitter running high, should be considered marginal failure.
Failing surface scan = bad, guaranteed.

Any DVD, nothing special to M-Disc (just another brand/make of DVD)