Thanks for the helpful advice in dealing with people Ernst, but I thought I did describe in detail what my goal was. I will add more detail, as so far, I've gotten nothing but flak and insults, with only ONE account of swapping, answering my purely technical question.
I have a 5' 6" 118 lb wife. Covid has occasionally left her alone at our country place when I have been forced to travel, and it looks like we are not going back to the City anytime soon. She expressed concern, so I bought her a Shockwave, as it was the smallest and lightest legal Not-A-Shotgun one can find, and it was a Mossberg, not a "Freedom Group /
Cerberus Capital Management" piss-poor QA product.
But... recoil. So, looking at options, the Knoxx Breachers Grip Gen III seemed best.
But, it makes the safety.... awkward, and my practice for a solid 50+ years of shooting shotguns has always been to consistently make the sounds "Click, Boom, Rack, Rack" in that precise order, so the safety stays on until weapon is being aimed at target.
So.... move the safety.
And, lo and behold, the Maverick 88 puts the safety on the trigger group exactly where it "should be" for the Knoxx grip.
Do I care about resale? No! The old trigger group can slide back in any time for resale, just as the birds-head grip can bolt back on.
Do I care about warranty? No! See above, the gun can go back to "factory stock" in 10 minutes, as I can disassemble and clean a Mossberg in my sleep by now.
Do I care about "court"? No! If the gun is ever used, there will be a dead person on the floor, and a wife who fired only because she was unable to run away. We are not about to use a gun to protect "stuff".
Do I care about the "hole" where the tang safety went? No! I can 3D-print a smooth flush black cover plate to fill the depression, and put a nut and washer inside the receiver to keep it in place. Again, the stock safety can bolt back in any time.
Do I care about staying short AND legal? Yes! Why else would I pay the premium for a Shockwave, when I could have just started out with a far less expensive, and "otherwise identical" Maverick?
So, that was my question - I'd rather not spend yet another $30 or so on a Maverick Trigger group, and I figured that I couldn't be the first to come to the obvious conclusion that a Shockwave might need some recoil reduction, or the only guy to have a shawty who is a shorty.
I'm not a cheapskate here, I've already added the usual fittings one wants in a "home defense" weapon: Streamlight TL Racker, Crimson Trace LS-250G green saddle laser, composite heat shield, and I even drilled and tapped the heat shield to move the bead onto the heat shield "just because". Oh yeah, and the Delrin follower... why? Because a physicist like me looks at a stamped sheet-metal component with a spring behind it, and thinks "that sucks". I've had Delrin followers since they were first offered in my other Mossberg pump, feels much nicer.
What is my wife going to actually DO? She'll shoot at ground targets with this every other month or so to keep skilled, out at the Hudson Farm complex in NJ, and maybe, just maybe, she'll do some skeet shooting now and again with break-open double-barreled "real shotguns", either with me, or one of the all-ladies gangs that have formed out there. But over the short term, or if she is not so social about shooting, recoil is the thing that will limit her willingness to practice shooting.
But the shockwave is a single-purpose weapon, and will only be used under a very stressful scenario when lots of s**t has unexpectedly gone lateral, so lots of practice will be needed, and every possible "ease of use" factor needs to be addressed.
I do hope this helps the far more experienced and far wiser subscribers to this interwebnet thingy who were so helpful with their many suggestions and comments to understand exactly where I am coming from.