Ok. It sounds like you want to make it easy to remove the regulator (or the feed hose to the regulator/crossover if you have two tanks hooked up to the crossover) from a tank and put another one on without a wrench?
Why not just replace the fitting that you show in the top photo with a different one? Here is a pic of a high pressure fitting (the "tank side" of the regulator is known as "high pressure" in propane-speak) that might do the trick:
That green part is an "Acme type 1 wrenchless tank connector". You can google that to see many variants of the type.
The fittings generally attach to each side of the regulator with standard plumbing connections. Typical connections are 1/4" or 3/8" and either "pipe thread" (like it says... a threaded pipe cut square on the end) or "flare" (where the end of the pipe has a machined bevel or shoulder typically at 45 degrees which seats to the corresponding section and forms a tighter seal than the threads alone). The brass section at the end you are showing in the top photo can be removed with a wrench and replaced with something like the Acme type 1 in the pic above. If you do that, be sure to use the same type of fitting (yours looks like 3/8" to me. You can take it to a good hardware store to confirm. You'll know whether flare or pipe thread when you remove the current one. Whichever it is, use the same.) also, use Teflon (EPDM) tape rated for gas (usually yellow in color... it's double thickness) and after installation test for leaks with a bubble solution which you'll find on the shelf next to the Teflon tape in the hardware store.
That's not a quick disconnect solution... but it's quicker than a wrench. If I answered the wrong question or you want to talk about QD with the Sturgis or Camco fittings that I use, let me know. There's a pic of my generators with hoses, tee fittings and QD setup in my photo gallery if you're interested.