I spoke with Tyler today and I'm going to make a post to explore the level of interest in an aftermarket, more vertical, grip skin and see if there is enough potential market to justify the non-recurring design effort.
As for butt pad, perhaps you have seen where I posted that I replaced my J Allen butt pad with a grind-to-fit thinner Kick-eeze recoil pad (IMO, a real recoil pad) to reduce LOP a 1/2"
Now, of course this will do nothing to provide vertical, lateral, and rotational adjustment to the pad.
But, there is a LOT of adjustable pad hardware out there that is very good. I personally like the 100 Straight product as its the thinnest that I'm aware of (doesn't add a lot to the LOP or weight) with hardened steel where needed. I have one on a K-80 shotgun, been there for a very long time, and I'm quite happy with the quality.
100straight-com.3dcartstores.com
All of these kinds of hdwr are also grind to fit. So, if you can grind to fit a recoil pad to a J Allen (and you can) then you can grind to fit butt pad hdwr to fit also.
The rub is in chassis/stock hole spacing for mounting the hdwr to the stock. It seems that EVERYBODY in the entire world (well, perhaps an exaggeration) but J Allen uses a standard 3.125" hole spacing. The J Allen holes on the chassis (and butt pad) is less than that by a bit (sorry, can't remember exactly off the top of my head).
For the recoil pad we ground on, we kept the top hole and added another one north of the existing hole that the pad came with. Then mounted it up.
The same should be easily done with adjustable hardware, only bit I don't know about is some sort of steel insert for the hole to provide some strength as is the case with the stock mounting holes. But, you smart gun smiths and machinist types could probably solve this with your eyes closed.
Just a thought.