Well, it isn't a recent topic as the search brought up a few hits. So without delay.....

Enable Friendly collisions everywhere "except" (maybe) on the Runway, spawn points, and CVs. Did I miss one?
Would the Vulching by a horde slow down? Sure. Would folks fly a little more conservative...yes again. Would it be a popular idea, maybe not...well not likely, but a poll in the Arena Message might be in order.
Right now we collide with everything else! My favs, #1 the ground, trees, CVs, invisable building pieces, hills, mountains, enemy plane parts, why not my squaddies! It will require increased SA, communications, and the 4 on 1 or 40 on 1 will dissipate. Each will take a turn now trying to bounce an enemy...cooperation would rule out.
Since F3 (External View) is enabled on the runway, maybe even a code where each spawn has different coordinates, with 3-4 on the runway and the rest in a line on the taxiway
if collisions on the runway is the
only other option. ie
Collisions On/Off may be the only switch now. Just a thought in passing. I have flown in the Racing Events with it on and it is really a hoot!

Talk about "white knuckles" and a deathgrip on the Stick and throttle.
Maybe a Thursday (or other day) Treat - like a Titanic Tuesday event, on a trial basis.
-Sits back with flak jacket strapped on me seat-