This sounds like an x-y problem.
You are probably looking for easier separation or a nicer surface on your red area, and what you are actually asking for does the opposite of that. (Probably. It's complicated.)
For tower-like supports, you will have a structure similar to infill used to get to the right height, then an interface layer (kind of like a raft), then the print supported on top of that.
You think (I assume) that you could have fewer points of contact, and this would mean the printed surface is more perfect. That's mostly wrong. With fewer points of contact, the hot strands are more likely to droop and fuse with the support. It's kind of like the trick where a person lies down on a bed of nails: more points of contact means less pressure, which means a cleaner surface.
What you can do instead is play with the interface layer (the "roof"). IIRC, it will only allow multiples of your layer height, so you don't have that much granularity. That's fine. try bumping it up one layer and see if that gives you better separation. You can also try making the roof a little beefier, so it snaps off as a single piece more often.
If for some reason you really, truly do want fewer points of contact, disable the support roof (or set it to height zero and turn support density down. I do not recommend this unless you have something specific and weird going on.