Having cooling set to maximum while printing dense supports can really help breakaway supports to come off with minimal issue. A simple checkbox for cooling on dense supports would be really useful as a feature. I have figured out how to do this with scripts, but it only works if there is only a single island of dense support in a layer. It fails to toggle cooling off for the part itself if there are multiple islands of dense support in a layer.
Scripts
Pre Layer Change Script
M106 S0 ; Dense support cooling off
Post Processing
{REPLACE "; feature dense support" "; feature dense support\r\nM106 S255; Turn on Filament Cooling"}