Hi Dominik!
Our terminal based connections are using 3rd party components (rebex or putty). In case there's a PuTTY fork which supports mosh, you can try this approach to integrate it:
https://www.royalapps.com/blog/prefer-kitty-or-extraputty-instead-of-putty
Alternatively you could try to integrate Cygwin using the external application connection:
https://content.royalapplications.com/Help/RoyalTS/V5/index.html?reference_externalapp.htm
https://www.royalapps.com/blog/integrate-powershell-in-royal-ts
If rebex implements support for mosh, we will, of course, light it up in Royal TS as well.
Regards,
Stefan
Dominik Zajac