I missed the behavior of my putty terminals enough that I kept searching. Today I replaced my external-connection for WSL (wsl.exe) with a normal terminal (which I use putty for). I simply needed to install/config ssh in WSL and secure it. Nothing to do on RoyalTS side except create a normal terminal with defaults and whatever port you configured locally.
See https://www.illuminiastudios.com/dev-diaries/ssh-on-windows-subsystem-for-linux/ for step by step instructions on setting up WSL for it.