Well, Slic3r has gained some speed back when I unselected “Avoid Crossing Perimeters” without any issue on my first test print. Thank you @Devin_Grady !
I’m still going to give MatterControl a good try.
@John_Pacyga no problem. It usually causes too many unnecessary moves anyway in my experience. I’m thinking about a “make segment at most 1.3 times longer” option or something but still getting my feet wet in the Slic3r code.