I don't know if it has ever been covered. However when Dalinar forms a bond with the Stormfather, the Stormfather specifically says that he will be a Radiant with no "Shards." A few things stick out to me about this:
1. Shards is capitalized
2. Shards is plural.
The rest of tWoK and WoR uses this term to encompass either shardblade(s) or shardplate(s). If you make the assumption that wielding two sprenblades/shardblades from the same spren is unlikely, then my only conclusion is that he is referencing both a shardblade AND shardplate. Why use this word if he only means a blade.
If that's true, its a clue that Shardplate involves some sort of physical manifestation or physical interaction on the part of the bonded spren. Of course this all relies on Brandon Sanderson being that meticulous (he usually is). Anyone else have any theories to add?
I apologize if this wording in particular has already been discussed. If it has, can someone link the thread, I tried searching but didn't find anything since these words are just so common in the forums.
