It does, but that selects and moves the cells not the objects and then redraws the cells? Actually, going back to have a play I see that it does allow some modification of existing objects but it isn't terribly flexible.

I've just done a quick search and found one that I've not spotted before, which is a bit closer to what I want in that one respect, but not nearly complete overall (and not seen a check-in in 8 years): https://textik.com/ - that might illustrate the key difference that I see missing in asciiflow.