A Shield Plus may fill a nice sweet spot between the P365 and the 43X. Not as easy to conceal as a P365, but a shorter grip for a given capacity than a G43X/G48.
I have a P365XL and a Shield Plus, and used to own a Shield 1.0. I, and others who have shot the Shield pistols back-to-back with the P365XL, thought that the Shield has a flatter recoil impulse. I haven't shot 4.0" examples of the Shield/Shield Plus, so I can't comment on those.
I have shot early examples of the G43X and G48, but it's been too long for me to remember how they shot besides one had a notably worse trigger (Monday morning/Friday afternoon gun, perhaps).
When it comes to AIWB carrying, I do find that my 3.1" Shield Plus has more of a 'keel' effect with the 13-15 round mags than the 3.7" P365XL. This can be mitigated by using a 4.0" model holster or attaching a wedge.
Good point about the AIWB, the holster I bought was "longer" than the usual 3.1" length for that purpose.
I'm in MA so we don't have to "worry" about 13 & 15 round mags. The 10 rounders with the pinky extension work just fine.
I purchased more of the S&W pinky extensions, they're slightly different than the Pierce ones and I like them better though either works just fine. They don't list them on the web site but you can call and they can place your order for them.
If you're interested - Part Number: 3015715 "Buttplate, Finger Rest"