Make the tabs, caption buttons smaller at compact.
Make the tabs, caption buttons bigger at touch.

I can't recall which app I saw this in recently, but I thought it was a good idea. Firefox maybe? Definitely plays in to the work being outlined in #3327 / #5772.

Should this be it's own property, or a collection of other ones?

tabRow.height
tab.fontSize
tab.padding

All seem like properties the user would need to configure, but I'm not really sure now if all of them make sense atomically, or if a user would even want to tune them separately.