I also used to use griddle, and then saw it wasn’t working with the latest version of serialosc. I think griddle depends on zero-conf, so you’d have to move back to a zero-conf version of serialosc.maxpat to enable griddle.
I’ve found that the new serialosc can span in apps that are written to support two grids. Eg monome sum can span, and some of stretta’s BEAP applications can span, though they seem to assume that the first device is a 128 (minimum 16 cols). I’ve been hacking the drum sequencer to get it working with two 8x8 grids, but it’s a bit tricky to get exactly right.
I don’t know if there is a general solution that is like griddle with the current version of serialosc - but I believe an new version is in the works which supports spanning natively. See tehn’s latest post on that.
Let us know what you learn.