"Patch levels" for Maven-controlled projects are somewhat of a contradiction. Maven is based on the idea of discrete versions of artefacts, not on versions+patches. Patches in the old-fashioned where you could just do a brute-force binary zap are virtually unheard of any more (in part because in modern-day systems, the compilers optimize intensely on every source change).
If you wanted to scan a produced artefact for component versions, I suppose you could create a mojo for that, but it seems like it would probably be simpler to merely change the dependency versions in the POM to their required levels and do a maven clean/rebuild.
Customer surveys are for companies who didn't pay proper attention to begin with.