Switching Epson XP-950 to use epson 512(106) ink

[Ink stained Fingers]

I had a look to your profiles, there is the Epson XP-950 Premium Luster, that's tuned to cover tolerances in inks, the printer hardware/driver and manufacturing batches of papers, it is smoothed and averaged for that reason but nevertheless completely usable.
icm Profiles can be generated in 2 software versions - V2 and V4, both differ somewhat, V4 is newer, and not all graphics/printing software can handle V4 profiles. Differences are there, yes, the industry members of the ICC color consortium agreed on that newer version some time ago, differences are in the perceptual rendering, the transition area between colors in and out of gamut. But you cannot generally say that one version is 'better' than the other version. The Epson profile is V2 to make most universally usable in any software environment.
Your profile 'Kodak Ultra Premium' is of V2, and I can display those in a gamut viewer Monaco Gamutworks or Gamutvision, Gamutvision locks up with a V4 profile, so I only can discuss V2 profiles.

The wider translucent gamut body shows the Epson profile, the smaller one shows the Kodak Ultra Premium profile,
this is slightly smaller , both profiles have the same black level, the bottom tip.
This is the status at a medium lightness of L*=50, cutting through these volumes.

The green line covers a smaller color range, but I would think that this is only visible in prints in direct comparison and if such prints actually contain colors between the green and the red line.
It looks somewhat similar at a lower lightness, here at 20%

The Kodak profile is somewhat narrower than the Epson profile.
I cannot display your 3rd profile Kodak ultra studio, that is a V4 profile which I cannot display with my old software,
and Gamutvision locks up as well. This alone shouldn't be a reason for you not to use V4 profiles but as mentioned
you can get into some hiccups with V4 profiles with no real benefit otherwise. So I cannot give you an opinion about this profile.
You can easily set the version in the new Color Munki version, there should be a tab with profile options to select V2 or V4.

 

[kcgoatboy]

Sorry been busy here. Here's a v2 paper profile.

 

[Ink stained Fingers]

thanks for coming back with your profile data, I did a quick display of those, with an old Monaco GamutWorks program, I'm just used to it, you can do a similar analysis with Gamutvision.
Let me first compare the profiles of the Kodak papers

The green shape is the gamut of the Kodak Ultra premium, the red body the Studio Gloss which has a bigger volume, the black point values are about the same. The wider body is visible at mid luminance L*=50

The gamut is as well wider at darker colors , here at L*=20

and at L*=8

There are more colors available for print in the darker range, this could be visible with more detail definition in the darker
ranges of a print.
Le me compare here the Kodak Ultra Studio with the Epson XP-950 Premium Luster

The blue shadow is the Epson gamut, red of the Kodak gamut, they are quite similar overall, similar volume, similar shape which
is as well visible at L*=50

Those differences should not be visible in normal prints, and probably only in direct comparison with prints which actually
contain colors between the boundaries.