Phooey. Oh well. Honestly, I probably wouldn't buy it even if I could carry it around in that rig.
I don't really care for shotguns to begin with, and to be frank this strikes me as being pretty much useless for anything other than being a range toy.
See, I am just the opposite. I would buy one to put behind the truck seat. I was actually looking into it, when I saw a discussion on PAFOA that more or less spelled out why PA law says it is illegal.
What types of shotguns have you tried? I ask because I was never a big fan of shotguns until recently. I have a Benelli that was my first shotgun, and while a quality weapon, it doesn't mesh with me well. Then I bought a plain Mossberg 500, which once again is a fine weapon, but it does nothing to excite me. Then I got into hammer doubles, and I like them, I do, but more for the historical/cultural significance and less as 'weapons.' They are for shooting groundhogs, not people.
Then our Illustrious Leader had his upset victory over the Witch, (Sieg Heil!) and part of my celebration was to buy a Remington 870. An 18" Wingmaster model, the serial number says it was born in May 1980. This shotgun was well worn, and the stock needed refinished. After refinishing the wood, cutting it down and installing a recoil pad, and replacing the springs, I have found that I very much like this gun. So much so that is one of only two of my guns that have names. It is a keeper.
My point... Try different types of shotguns. What works for me might not work for you. Try different brands, too. When my only experience with pump guns was the Mossberg, I thought them the dumbest idea ever... Now knowing the Remington, they are my favorite type of shotguns.