@cal,
I think some users have tried to use option sets in plugin fields as data sources and have faced issues, because the corresponding getter and setter interfaces don’t match to custom data type. E.g. getting the bubble id of a custom data type makes sense but option sets dont have such a property. I think either the interfaces need to be made to match / there should be a differentiation in plugin builder interface between ‘app type’ of custom data and ‘option sets’?