I’m not sure when this was added (or if it were somehow always there!) nor found it in any documentation (I checked right after reading this update’s release notes that sort of mentioned it, but it’s possible the manual hadn’t been updated yet…but then I started playing around trying to figure out what they meant), but in grid recording mode you can do a standard ‘hold button(s) for fill’ via TRK+PAGE. The lack of this was always an annoyance for me while programming said fills, but seems in fact to be possible!
I’ve seen this brought up a few times recently so wanted to share; apologies if I missed a previous topic on it.