I see that there was a feature request logged in March for supporting TMaps in Blueprint:
Does anyone know if this is on the cards yet?
Lack of TMaps is one reason I end up going back to C++ from time to time to setup TMap insert/get UFUNCTIONs (which is a bit jarring considering most of my work doesn’t need C++ and can otherwise be easily accomplished in Blueprints itself). I realize there are workarounds to emulate TMaps from within Blueprints but these feel less than ideal.
Map/Dictionary style support feels like a core data type one would need for just about any kind of programming be it visual or code based.