Is it possible to say that I’d like the height of a faceted chart to be something (say 100) no matter how many facets end up being generated?

So, at (pretending) facetHeight: 100 if there were two facets generated, it would be 200 plus axes and spacing… if there were 7 it would be 700 plus axes and spacing.

This is not possible at the moment, you would have to write height : 50 + 100 * d3.groups(data, d => fy(d)).length. Please open an issue so we can discuss it on github?