In the late eighties I used to use E, an editor developed internally at IBM. My dad had retired from there by then but got it from ex-colleagues. I see you can get it from here now https://winworldpc.com/product/ibm-e-editor/3x
Already mentioned is Brief, I still have the light green box on the shelf. This was ultra customisable but like many, just used it as-is. A super compact and snappy editor was the one built into Turbo Pascal. IIRC it used WordStar bindings. It was so compact on CP/M that I kept the whole integrated editor/Pascal compiler on my 8" floppies just for editing my COBOL assignments, later on using the DOS version in Turbo C / C++. I also used WordStar on those OSs and I'm sure lots of you will fondly remember the LIST viewer by Vernon Buerg. I loved that program.
