Yes, we know that drum set notation is not yet possible in Dorico (it’s listed on the list of things that Dorico can’t yet do but which we plan to address in updates on the main Dorico product pages on the web site, so I hope you weren’t surprised to find this out when you bought the software).
We have a number of big ideas about how to make this work really nicely, and I think you will be happy with what we come up with.