Unexpected behaviour when combine scales = "free" and axes = "all"

I love the new feature of being able to add axes and their labels to interior facets (See #4064). But it didn't combine as I expected when using scales = "free" as well.

This is an example with mpg:

library(ggplot2)
#> Warning: package 'ggplot2' was built under R version 4.4.3
ggplot(mpg, aes(cty, manufacturer)) +
  geom_point() +
  facet_grid(year ~ drv, axes = "all", axis.labels = "all", scales = "free")

^{Created on 2026-09-14 with reprex v2.1.1}

In my use case the separate panels are different versions of a model and the names on the y axis are terms in the model and the terms in the model vary in the different versions so it is confusing to have all of them labelled. It would be perfect if the labels could stay in the same location, so that one can read across a row to compare between facets, but with the labels blank for the manufacturer levels that are not present in that facet.

This only really makes sense with discrete variables but it would be super helpful!

Start by running the provided mpg example with facet_grid(), scales = "free", axes = "all", and axis.labels = "all" to reproduce the panel labels. Trace how facet_grid() combines free discrete scales with interior axis labels. Done means labels remain aligned across each row while staying blank for manufacturer levels absent from a facet.