Not really, but you may be able to get somewhere close by tricking UHT and wrapping things in #if CPP ... #endif Blocks. The engine uses these in a couple of places as well to handle some of the common aspects of such structs.
In your case you may need to remove the UPROPERTY macro and then handle garbage collection by implementing AddReferencedObjects. And you’d obviously lose the EditDefaultsOnly support and have to implement a custom property editor.