Alas, I tested with a Roland controller keyboard through iRig midi today and as Ludwig said there is none of the problem that I’ve described with DrumsXD via virtual midi, and my Fishman going through the Duet, or what smeeeth is getting with his virtual midi programs.
So I guess a fix for this will probably not come soon.
Oh, well, my Beatmaker workaround works and only adds a little extra time/inconvenience.