WordStar isn't that difficult once you master the diamond keystrokes—E,S,D,X—and the keys adjacent to them. In fact, WordStar's control key 'diamond' was very well thought out. After one mastered the sequence which probably took several days one could enter text very quickly and efficiently. I just found this site which provides an excellent explanation:

https://benhoyt.com/writings/wordstar-diamond/

As I mentioned above I ran WordStar on multiple operating systems and I still have it running under an emulator under Windows.