In Multitrack view, the facility be made available to select any track and to lock that track's height at any desired setting, so that it is unaffected by the global resizing of the other non-locked tracks. As far as the user interface is concerned, this could be implemented by adding an 'L' button in line with the 'M' 'S' and 'R' buttons.
The ability to globally lock, globally unlock and globally invert the lock status of all tracks;
The use of a 'modifier' key, such as 'CTRL', to 'steal priority' away from currently locked tracks, much like the current operation of the CTRL + Solo button combination.
A facility such as this would allow, say, the video track to remain locked down to a sensible size, or a select few unlocked tracks out of many locked tracks to be simultaneously resized in order to aid workflow.
I've recently finished working on a 89-minute long film timeline that had 199 tracks, and to have been able to selectively simultaneously resize track heights would have speeded up the workflow.