I used it quite successfully for an official sequel to an old DOS game a few weeks ago, and it even got to the point where it was pretty trivial to patch the js-dos ZIP bundle on the fly to modify how the original DOS game worked.
One thing I will say is that this so far has NAILED the experience I remember of loading the game. Thinking the PC had frozen, only to finally be greeted with that gorgeous Maxis loading screen and opening animation.
I have not yet determined if the sim speed goes nutso on Cheetah like I remember, but I will edit this when I do.
DOS basically acted as a bootloader. But all of those OSes had the very weird feature that they could switch back into a virtualised copy of their bootloader.
I do feel that Wikipedia understates the importance of Windows for Workgroups. Internally, it wasn't just Windows 3.1 with networking. It was a trial run for the fundamentals of the Windows 95 architecture.
You can even get an extremely cool boxed version: https://www.etsy.com/shop/RetroeXo