Have you tried using Fluent Terminal? It is available on github and the Windows Store. To use mosh you need to connect via the quick connect menu in the top left corner of the program.
I haven't done a test yet, but the Fluent Terminal seems fast enough and doesn't eat up that many resources surprisingly. As a UWP program it feels very snappy (as opposed to Hyper being a full on electron app using 200MB for simple text output!) I don't care what technologies they use to build a program, as long as it works. I haven't experienced any hangups using SSH, so it's good enough for me.
I tried a ton of them for a while and the microsoft terminal or wsltty both use the least amount of resources, open the quickest and have the lowest input latency.