I just bought a second remote, a spare wheel assembly and several spare cradles. How do I tell the difference in the remotes and if my spare wheel and cradles will fit both of my remotes? My first remote has never given me a problem and it was purchase when the DCS system was first introduced.
The explanation from MTH RD here seems to indicate the separate piece part cradles are only compatible with pre-2020 (so any remote that is not labeled as 50-1038 on the back) remotes. (I had the same question a few posts below the linked one). It looks like they will not sell the new design cradles separately, only as a full thumb wheel assembly.
So unless your "just bought" remote was by some miracle an old 50-1002 version (seems highly unlikely since there was a pretty wide spread out of stock situation before these new remotes recently showed up), the cradles you bought will only be good for your original remote.
It sounded like from the description that the new thumb wheel assemblies are compatible with all remotes (though with a different wiring instruction that is to be included with the part). So a new thumb wheel assembly can be used in an older remote if needed.
I don't think the specific part of your question regarding an older thumb wheel assembly being usable for a new remote if needed was explicitly stated. It sounds logical (though I would suspect it may involve a wiring difference), so hopefully MTH RD will respond to that part to clarify.