First, use "IP" marker sparingly, just enough to cover
the extents of any DRC violation.
In the past when I had control of my own PDKs, I
have gone to the lengths of making a DRC-ignore
logic that was specific to the layers (I only cared
about a couple of fixed cases, not general blocking).
If you had (say) a min-poly DRC, I'd work on maybe
a drcIgnorePoly construct that could place a texted
polygon covering the fault, which -only- affects
poly min rule check (and would have no influence
over the Met5 case you pose).
Of course if you're not allowed, or not up to making
private versions of DRC decks, maybe you just have
to constrain your DRC-blocking area-wise. But layer
comprehension (or even rule specificity) would be a
cleaner way to go.