If you use my repository, probably sometime soon, though I want to overhaul the mapper so it may take some time. For the general release, I'm not sure.
For the info, use setRoomUserData(id, key, value)
You can make your own mappings in value by using known delimiters such as a pipe or a unique sequence you want to implement.
You certainly can if you implement a layer between Mudlets APIs. We officially don't have plans to present our API as a class - we present low-level stuff, and then frameworks build on it as they like (Geyser, Vyzor).