I have also found that Polylines can be displayed on android, but attempting to edit the geometry results in a crash

Multipolygons are supported on Android devices when imported from a shapefile but users can not create or edit multipolygons in the field. iPhones can not even view multipolygon records unfortunately. The majority of my organization uses iPhones, so it would be great to see support for those devices. Currently using some workarounds that are not ideal.

Multipolygon Support is easily one of the main things my organisation is needing to get rolling. It would open up capabilities largely. Allowing for support of all our tenure mapping.

Yes, I agree, this would be very helpful!

Use case: managing multipolygon APN's as a singular Fulcrum record.