Variable interline spacing within message block

It's cool that we can have variable interblock spacing with the new UI update.
But can we also get the option to set interline spacing then? [Measured in points, not pixels obviously.]
Every bit of space that would be saved on reduced interblock spacing is lost on the increased interline, which is actually pretty harsh on readability.

What's the point even if one counteracts the other.
To make things more compact and cover the freed up with annoying popups that can't even be disabled?
But it's not even more compact in the first place.