Hi. Recently (August 2019) this article in French has described in detail the adding selection mode (Shift + F8) performed using only the keyboard.
I’ve been trying to use it for days. Apparently it highlights more blocks, but selects only the last one each time. I checked it with and without macros.
In addition, the highlighting remains permanent. If you delete the whole document, rectangular areas of the screen remain highlighted, as if they were represented on a superimposed graphic layer.
In your LO, performed with the keyboard alone, this selection mode, does it work?
If it works, are you able to record these selection operations with the macro recorder to report in this discussion?