Cadence layout isn't the best for MEMS structures, other tools
have been more aggressive in adding support for the weird
(from an IC perspective) geometries. And it's certainly the
most expensive tool for the job (unless this is Somebody Else's
Problem).
I've seen some other layout editors that make noise about
MEMS suitability; I'm sure you could turn them up with a
search, I forget their proper names. But my take-away was,
they were sort of weak in other aspects and of course the
PDK is the real obstacle in adopting alternative tools.