This is an idea I'm going to try out.
The key part is a Nobile stainless steel swivel which has a hole for a flagging line to pass through. I have drilled the hole out from 4mm to 6mm using cobalt drills and smoothed off the entrances to the hole.
The swivel worked OK for flagging to both front lines (although it wasn't that good at swivelling
), but to flag to one front line, you will have a line with connections going through the hole, so it needs to be bigger.
This is a Switch bar and at the top of the centrelines is a Slingshot Choad Ball. One front line connects to the top of the choad ball and the other connects to the white Slingshot Bungee Line through the choad ball.
The plan is to have a minimal sized replacement for a chickenloop below the bar. The front lines can be untwisted by twisting the top of the Nobile Swivel.
The Q/R is a Wichard.
The first and second pictures are of the Wichard reversed. The low friction ring is a Wichard FRX10 which has more meat on it for grinding than an Antal ring. It takes quite a lot of careful grinding to make the ring fit the Wichard. To operate the Wichard as a push away Q/R there is an 8mm screw ground down to fit and a couple of plastic balls ground down.