This is new piece of the story
I thought I had mentioned this before somewhere
. It was only recently that I realised what had gone on!
There is reletad IS WordStar document file, dated 1985.08.21:
Yes that looks very much like it was written (by MRL) to prepare for Robert Madge's Japan trip!
There are other Wordstar documents about possible enhancements to IS-DOS, talking about enhanced batch file commands and even possible multi-tasking. I think they were all part of the same trip!