@Fcasioli
"some different height for separator bar"
It's already shorter (smaller height) if you use "slim padding" for the message list, compared to when "slim padding" is not enabled -- and I can see that you're using slim padding.
Maybe I should make a larger adjustment, for smaller height.
PS ----
Aren't you supposed to be drinking Lambrusco and eating Prosciutto right now?
Instead of posting on some Internet forum?
Happy birthday!!!