This was a marketing post, not a technical one. Unless we see any git branches or ROM teardown we won't know what they were doing. I highly doubt that they did any kernel patches though.
I have the same and use it with Linux. I can recommend it after fleeing from Csnon's color cardrige fashism. The epson uses refillable ink, without any electronics. You can buy 3rd party ink by design.It was designed during the chip shortage where it wasn't profitable anymore to make defective-by-design chipped ink cardridges. Lucky us.
Is there a reason why most of the EU is missing from the data set?