Well, we've been told that once you code for one of the upscalers, the others are easier.
Indeed, homie has lost the plot of this thread. I.E. manufactured outrage over DLSS missing from titles sponsored by a competitor.
But seriously FSR4 is only supported by RDNA4 cards, which are still going to be a fraction of all AMD cards out there, which is an even smaller fraction of the total number of cards out there when AMD has an 8% market share.
My dude, 8% shipments last Q does not translate to total percentage of AMD graphics users. Every poll by tech sites has 1 in 3 respondents using AMD. There are over 6 million Steam Decks sold, and millions of other AMD based handhelds out there. Millions and millions of mini PCs, notebooks, and desktops with AMD APUs.
So I understand a small dev focusing on DLSS especially if NV has a team that offers solid support.
You are almost there, you can do it, I believe in you!

Good natured ribbing aside; That's why this thread is so disingenuous and cringe. Sponsorship and support in exchange for exclusivity has been going on for decades. That tech news outlets were joining in, demonstrates what moves the not so invisible hand of this particular market.
That said, including XESS is definitely a head scratcher unless Intel literally sent people to code for the devs.
I doubt it. Intel isn't exactly throwing around money and lending out its people anymore. The more likely explanation is because even the DP4a version of XeSS is almost always better than older FSR versions. I have no idea if the int24 fallback is still a thing? That might look worse than FSR, if that's possible LOL.