I can supply some information on fabrication, at least!
Our typical vendor (like most of the USA based EuroRack world) has been Metalphoto of Cincinnati. This vendor uses a proprietary process for printing under the anodization layer (or something like that) that makes the prints very scratch resistant and permanent. Also they have been a big trouble to work with – long delays that have held up production, QA issues, and very expensive ($15-$25 per panel, and much more if your order size is less than 100 pcs.) Last year they announced prices going up +60% due to the rising costs of aluminum.
All of Visionary series, all of Expedition series except the very first print run of Visual Cortex, use Metalphoto frontpanels. With the first run of Cortex, it is a metalphoto BLACK print, but the RGB colors were silkscreened by a local company here in Portland. This run of panels is the one that has poor adhesion issues and does not hold up well in the long term.
With Vidiot, we were growing in size and decided to handle our silkscreening in house. The first 100 units with enamel inks looked okay, but this really improved once switching to epoxy inks (Nazdar ADE series.) Epoxy inks like these are used for industrial and appliance printing, like the markings on your fridge or a car.
But that was more work than we wanted to keep doing here, so we had HLH Prototypes in Shenzhen start handling the printing – they had been doing our sheet metal work for the Vessel and Vidiot enclosures, and they did a great job of printing the rest of the Vidiot and Vessel units we made. They also moved on to handling all the sheet metal and screen printing for the Orion frontpanels. These prints, while not as resilient as the Epoxy inks were using in house, look great. And none of these have the same adhesion issues as the initial run of Cortex faceplates.
One of the big challenges for us, with panels and silkscreening, is color. There are many cases where we want RGB colors as part of the print, for legending reasons. With silkscreen that can get very expensive, and be challenging (4 prints have to be perfect before 1 part is done.)
Moving into Chromagnon/Gen3, we completely re-optimized our supply chain and BOM for all of our products – everything from a grounds up redesign of the circuitry using discrete components to new processes for fabricating parts. We made the switch to FR4 frontpanels – these are silkscreened white on matte black, but we use an in house UV printer to print a translucent overlay over some of the white areas when we want alternate colors. This works great – we get the sharpness and texture of a highly resilient silkscreen, and get to “colorize” that however we like with a UV cured overprint. Being a process designed for PCB fabrication, the FR4 panels are also extremely accurate when it comes to printing tolerances/alignment, and any milled slots are spot on.
Furthermore, with the FR4 panels they are so much less expensive than any of our previous solutions (our out of pocket cost is $2-$3 dollars per panel, rather than $20-$30 in some cases.) And they always show up in the mail on time, in a week (compared to minimum 6-8+ weeks with all the other options mentioned.)
Now naturally, FR4 doesn’t offer the same kind of aesthetic permanence as anodized aluminum. But it is much more accessible for being able to offer things like replacement parts and also, there’s not a $1500-$2500 hit on our cashflow, multiplied across all our modules, when everything needs panels, and an indeterminable wait that has often held up our production schedule. So one of the big things I like about it is that it’s much easier to offer variants, and it lowers the threshold of “trying out a design” even if it’s not something that has to be allocated a big segment of our resources.
So, FR4 replacement panels, that is a much easier proposition for us. We have most of the Expedition panels converted to ready-to-order design variants, so we could stock some replacements and offer them affordably to you.
I would also like to offer some “deluxe” front panels for Gen3 and beyond. For that we can go straight to the optimal solution, which is CNC engraved anodized panels with color infill. But that’s going to cost $40-$80/panel easily, so I can’t build that in as the default option for everything we make. If that is something some people want and can justify affording, those could be offered as a bespoke option direct from us at some point in the future.
I know DIY art and so on is important to folks too… customizing can be part of building any kind of system, after all! I guess in that sense, I feel like part of DIY is learning. Learning to use calipers, learning to make dimensional drawings, learning to use scanners, learning to use Adobe Illustrator, how to format print files, etc. To give away the source files would rob you of the opportunity to learn these skills, and put your own energy into your project. So I’ll gladly help you learn, but I’m reluctant to give the source away. Because your DIY knowledge is what’s in it for me. 
Customization or alternate art projects are not quite the same as needing a replacement part for a piece of gear you bought, though, of course. And I suppose that’s the question of the moment.