Another solution I’ve played around with, but it didn’t work super well… would be krfb-virtualmonitor

KDE’s remote framebuffer tool for making a virtual monitor to VNC into. For me it didnt do what i wanted because I have 3 other monitors and I couldn’t assure that things would launch directly into the virtual monitor… and it doesnt support any sort of dynamic resizing… But there might be something there.

I also hope that this kind of stuff improves in the future because of the Steam Frame. In Tested’s video, he calls out that he can only stream games at 21:9 if his 21:9 monitor is on. And other VR friends have pointed out the desire to dynamically resize content in the headset. So maybe this will get better in the future.

For me the issue is that i have a OLED 21:9 desktop, and streaming to my Steam Deck risks burn in on my desktop, and annoying black bars on my steam deck… I’d love to just have a 1280x800 faux monitor to stream to my steam deck, nothing needs to be visible on the desktop (headless, like you want).

But anyway tl;dr - krfb-virtualmonitor vaguely worked but not for what i needed. Virtual monitors are definitely a possibility

https://www.amazon.com/DIOOEER-Dummy-Headless-Adapter-Emulator/dp/B0HBQJQSDS

This might not be what you want specifically, but this is the kind of thing that came to mind. Basically a stub that feeds EDID data into the GPU so it THINKS there is a physical monitor with any resolution you want connected.

There are more advanced models out there that will allow you to custom program the EDID that it feeds, so you can use higher resolution or frame rate or whatever.

The market demand they are filling is cutting in line. Every time a scalper buys an item, a legitimate customer doesn’t get it. So genuinely SOMEONE is not getting a steam frame because of a scalper. That’s how it works. The steam frames being sold on ebay aren’t just magically generated by scalpers, they are the result of someone else getting pushed out of line.

Supply isn’t increasing because of them.