Switching printer vendors/makers may mean a change in ink as different makers use different print head mechanisms which require different inks. You seem to be chasing the holy grail of inks and paper combinations and, at least in this case, there ain't no such thing.
From Epson:
https://www.epson.eu/how-epson-measures-print-speeds/print-permanence-rating
Ink Type:Ink Type: Pigment-based Epson UltraChrome® HD ink technology
Fade Resistance / Print Longevity:Color: Up to 200 years
Black-and-White: Up to 400 years
While there is certainly a "manufacturer silo" that the companies want you to live/spend in, that's not unusual. Auto makers, for instance, have a line of performance parts that compete with third party parts makers to keep you in their revenue stream. Printer makers do the same.
While it...
I'm going to go out on a limb here, because I really don't know. But, in your first photos there is one that shows what I assume are the drain lines from the cleaning station and they, to me, look extremely clean. That is, it does not look like the ink is leaving the cleaning station as it...
Check the margins for the paper you are using. LR can be a bit confusing with this as, and I'm not in front of the application at the moment, you can specify this in the driver settings as well as in the print module.
Having been a software developer, test engineer, QA engineer, project lead, etc., for a number of years, the phrase "nobody would do that" points out just the things people actually do. Things labeled "Don't do this" are what people do. But perhaps I'm just a bit cynical...
I'm new at this, but, in no particular order, these questions come to mind:
Putting prints in the window automatically gets some UV protection but at the same time increases the thermal load.
Pasting prints may affect them. Particularly in hotter environments.
Heat laminating may also...
And if there is, they'll be "retro!" Kind of my thinking, but I've run into people who say it matters (as they look for something to read their mag tapes...)
You might take a look at Red River Paper, they have some nice luster papers. Here is a link to their descriptions of their papers and what they feel are similar papers from other makers. Get a sample pack from paper vendors to test for yourself; What other people think about a paper may differ...
Coming here first might have been useful as there is a long thread on just this topic. But, like many resources it is difficult to know when you don't know...