I can’t do better than this at the moment with My Nautilus plugin, 6017 meshes.
There are some problems I must tackle, here I use the automated version so it took polyline and extrude them using the mesh normal (the one you want to split).
mesh split.gh (7.9 MB)
I didn’t test with R7 but R7 has some problems. I hope they will be resolved in R9.
