Can I store a RealmList to customUserData?

I have custom user data enabled, so that the realm user is synchronized with a User record.
I would like to maintain a key that contains a list of objects. Is this possible?

Referencing the Chat app example, it seems like I should be able to add embeddedObjects to a list on the user and be able to access those objects in their entirety, but this doesn’t seem to work?
From the chat example

I’ve tried adding the objects directly to a list on the user object.

I’ve tried using an embedded object to wrap the objects I’m trying to get at. This also doesn’t seem to work.