I haven't looked at your multigrid example yet but the OSC commands work for me.
I use them in the All-Seeing-Eye mode of the VCS. As you know, there you can save all shared sound, mixer and instrument settings. In my case these OSC commands come from MaxForLive. So I can use the OSC commands Preset change, Dice and so on sequencer controlled.
You can find corresponding OSC commands for Kyma here:
Under "Controlling the VCS"
there is the command /preset,i
where i stands for the number you need for the thing e.g. 125 for 2.5%Dice and 128 for full Dice.
In Max I then use the object prepend, to prepend for incoming numbers (e.g. 125) - in this case /preset (without comma). So the message /preset 125 can then be sent to Kyma via OSC. For this I use the udpsend object.