Panels are different sizes when converting ggplot plot with facets

When converting a ggplot plot with facets to a plotly object the panels are different sizes. Margins are not subtracted from top and bottom rows so these panels end up being taller. This makes it hard to compare among panels. Margins for top and bottom of panels are equal so longer x-axis labels result in large margins on tops of panels with large spacing between panels and a low data-ink ratio.

library(dplyr)
library(ggplot2)
library(plotly)
library(reshape2)

p <- ggplot(data = tips,
            aes(x = sex, y = total_bill)) +
  geom_jitter(width = 0.1, height = 0) +
  facet_wrap(day ~ time, scales = "free_x", ncol = 2) +
  theme(axis.text.x = element_text(angle = 45),
        strip.text.x = element_text(size = 8, 
                                    margin = margin(t = 1, r = 0, b = 1, l = 0, unit = "pt")))

q <- ggplotly(p) %>% 
  plotly::layout(margin = list(l = 80, r = 0, t = 100, b = 100, pad = 0))

d <- rbind(q$x$layout$yaxis4$domain, q$x$layout$yaxis3$domain, q$x$layout$yaxis2$domain, q$x$layout$yaxis$domain)
df <- data_frame(lb = d[,1], ub = d[,2]) %>% 
  mutate(range = ub - lb,
         panelSpacing = lb - lag(ub))

Reproduziere das Problem mit dem bereitgestellten ggplotly()-Beispiel und untersuche die in d gesammelten Werte des y-Achsenbereichs. Beginne damit nachzuverfolgen, wie Facet-Panels und Layout-Ränder konvertiert werden, und überprüfe anschließend, dass das obere und untere Panel gleich groß sind und dass der Abstand die konfigurierten Ränder widerspiegelt.