Famae and Swiss Arms are steel guns though, so although arguably it could be conceived as unsightly, there are no concerns from a longevity standpoint, and the potential of a soft material deforming under constant pounding.
If that port looks like that after a few dozen steel cases, what does it look like once you’ve poured 5000 rounds through it?
Does that corner at the rear get rounded off, and does it change the ejection pattern? If it did, does it matter at all?
I suspect none of it will, but only time and rounds down range will tell.
These are not newly manufactured rifles (well the "DMR" version which has a longer barrel and target safety lol compared to our neighbours down south) but Americans have been enjoying these for several years now without and real issues surrounding this "problem".
I have been following the m10x since its inception and no one has ever said anything about having issues and there are plenty of reviews and videos on the web for people to see