@piever told me there was a method to do it by passing a vector of position tuples as a palette, but I never tried it. Maybe it’s worth opening an issue for it?
Thanks, that’s already very helpful. I would probably have expected the option under facet instead of palettes but the palettes = (layout=wrap(cols=3),) also would be nice.
I created a PR to add an example with the manually specified layout to the gallery.