Hello,
I would be happy to help. 
I’m not currently aware of any immediate plans to tag via USMLE-Rx, though we are always open to requests and suggestions.
The AnKing Step deck is currently tagged by the Amboss and UWorld question banks (and others), owing to their popularity and widespread use
There are some tagging programs currently underway, and you can find a bit more information on the monthly Step deck update posts, the most recent iteration of which can be found here: 👑 AnKing Step Deck Update #26 - #7 by Ahmed7
I can’t say I’ve used, or am familiar, with that particular site/program unfortunately, so I’m sorry to say that I’m not sure how much help I can be there
You might try searching by keyword, or by tag, or making use of some of the AnkiHub features such as SmartSearch and you should be able to find cards via any of these methods. The AnKing Step deck allows for searching via a number of different mechanisms in this way and I’m sure you can find the cards you’re looking for one way or the other. But those would be the tried-and-true methods of finding cards, in any case
Please let me know if that answers your question, and if there’s anything else I can help with.