Have any of you done this? Have you used the spreader bar set for a RR? Was your regular tarp enough coverage?

Clarification question. Are you referring to using spreader bars in a double hammock such as the ENO double nest? An option I suppose, but you will have a larger footprint and likely will need to make adjustments to your tarp to get coverage without having the tarp rub against the spreader bars.
I was using the Black Bird with Noah tarp when we met up, now I use the Ridgerunner and did go to a larger tarp. Having pullouts you can tie off or use bars designed to fit over the ridgeline and support the tarp at pull out points is important. Brandon makes these at 78" for best fit with the Ridgerunner and I am looking that direction. Without pullouts the slope of the tarp tends to result in spreader bars rubbing the tarp and exit/entry will require pushing the tarp up and away. I twiddled with my 10x14 CCS tarp last year and found a workable plan, but the Superfly with panel pull set up sounds very interesting.
The set up for the ridgerunner and I suspect other bridge hammocks does require a larger footprint. I can think of times up north the Blackbird would fit in much easier. The ridgerunner offers another level of comfort.

I already have a Super Fly with panel pull poles. My wife is going on a trip with me in the Fall and I was toying with putting 2 hammocks under the same tarp. I saw the use of the spreader poll on dual hammocks on Brandon's fish hook video.

superfly is 11'x10', i think it would work for 2 ridgerunners if you didn't expect hard weather coverage.

Looks like you run the ends of your gathered end hammocks through the ends of the spreader bars. The spreader bar just acts to separate the hammocks. I wonder if the hammocks would slide off the ends?

Not sure if you use whoopies or not. I do , and I used these Whoopie hooks made by Dutchware Gear. They have a hole to accept the spreader bar. Only one is needed for each hammock at the head end. It worked awesome fore us. I have a UGQ winterdream that is a bit bigger than a superfly. Worked for us. But it was also an August trip, and we had perfect weather the whole trip. I also own a Suprfly and think it might be a bit small to cover both in fowl weather. Dutch also makes hardware for straps that will accept a spreader if your not a whoopie guy.

trailcheif: "Not sure if you use whoopies or not. I do , and I used these Whoopie hooks made by Dutchware Gear. They have a hole to accept the spreader bar. Only one is needed for each hammock at the head end. It worked awesome fore us. I have a UGQ winterdream that is a bit bigger than a superfly. Worked for us. But it was also an August trip, and we had perfect weather the whole trip. I also own a Suprfly and think it might be a bit small to cover both in fowl weather. Dutch also makes hardware for straps that will accept a spreader if your not a whoopie guy."

Did these hooks ever slide off the end of the spreader bar?

Are you talking two gathered end hammocks? If so, I can recommend the ENO Fuse spreader bars. I'm eyeballs deep into the cottage guys, but this is a gem by ENO, and you're in it for only $30. Works with your existing suspension, and in fact, works really well just between the continuous loops on the GE. If you're talking two RRs, I cannot speak to that as you may need more width between the two.

Nope never had the bar come out. There is enough tension of the hammock against each other where it won’t come out.

I made 2 webbing pockets and use hiking poles as spreadbars for 2 RR hammocks. The tip end of the trekking pole fits into the metal portion of the suspension and is held in place by a BDB. The pocket was fixed into place with a zing-it beaner I made. Easy to adjust the length of spread with hiking poles. If you don't want to bring poles or don't have them maybe just make 4 pockets and find a stick that's strong enough. The pockets I made were a 10 minute project that have somehow held up pretty well over time with no more tinkering.

The only thing I'd make sure you do is to use different straps when hanging your hammocks. The first time I did a double I used the same strap around the trees and they shifted and pulled unless you get in and out of hammocks at the EXACT same time. Another option that I did was to bunk bed the hammocks, but that was much more difficult.

A tarp is much easier and you'll just need to do some experimenting. I found that using some sort of ball on the outer edge of the RR's isn't worth it and just tie downs further out was best.

I am contemplating hanging a BBXL next to a BB. Independent suspensions but hoping both will fit under my Super Fly.

AmarilloJim: "I am contemplating hanging a BBXL next to a BB. Independent suspensions but hoping both will fit under my Super Fly."

If you did the pocket idea or a variation you should have no problem doing that setup under a superfly.