I'm trying to enable unit stacking but only for certain units (settlers, workers, great people). I am aware of the PLOT_UNIT_LIMIT setting in GlobalDefines.xml however this changes the setting for all units. I've been searching for a way to change this setting per unit (or per unit type) but have found nothing? 
I really want to test this to see if it can help combat the giant end game clusterfudgs a bit. 1UPT is great for combat but I see no reason to cause huge traffic jams for civilians... if you could cut down on this then maybe late-game would be just a bit less tedious!

I really want to test this to see if it can help combat the giant end game clusterfudgs a bit. 1UPT is great for combat but I see no reason to cause huge traffic jams for civilians... if you could cut down on this then maybe late-game would be just a bit less tedious!