I have a great feature that would help when trying to cut down on the amount of support material used! Right now, it is great that you can split the process up to adjust the support fill percentage so you can use progressive support that gets denser as it gets closer to the overhangs. The only problem is that at low density, the supports don't fill the entire support footprint
(see pic 1) so when you start a new process with more dense supports, you get a lot of overhang and printing in air issues.
(see pic 2, red areas) If you could add something like "support wall" that adds a single loop wall around the entire support footprint,
(see pic 4, red line) then when you add denser support at a perpendicular angle, there will be no support overhangs. This problem is not as bad when you have more dense supports
(see pic 3) but it would really be nice to add this footprint "boundary" to catch the ends of the next finer support process layers. This would really cut down print time and material usage without risking a failed print from the support printing in air over these missing pillars.