Building a universal screencasting display/presenter: WiDi/MiraCast, ChromeCast, etc

I'm in the process of building a 2nd-screen solution for my workspace; something that provides ubiquitous connectivity, so that I can simply toggle any of my machines/mobiles/laptops/etc to use the screen on my desk as an additional monitor without needing to muck around with cables. In W10+, there's an option to "cast/project to networked display", that uses the WiDi protocol, a variant of the Wi-Fi Direct standard. Of course there's also the Chromecast protocol that seems fairly well integrated into modern-day browsers, though I'm not super familiar what a native protocol Linux/Unix/POSIX would use (mkchromecast is probably my best bet here). For now I'm using an old RPi3b+ running stock *Bullseye* & *XFCE* driving little more than a terminal (to remote into headless hosts), *Midori* (lightweight browsing, but hardly use it due to the load it introduces) & *barrier* so that I only need to contend with a single set of input devices. So far, so good. Where I'm getting stuck on is using this (essentially thin client) as a rendering sink, i.e. being able to cast Video & Audio (AV) ***TO*** this device, rather than from it. Now I know that this device hardware might simply not be capable of doing this (simple) rendering, so I have a NUC sitting spare for this purpose, i.e. once I've figured out the stack on the RPi, I can rebuild/redeploy it to this other box. There really does not seem to be much for something that seems to common-place on the W32 ecosystem. What I've found so far: - AirServer seems the simplest (best?) solution, but does not have a POSIX agent/renderer AFAICT - MiracleCast & LazyCast seem like promising solutions, but don't seem to work particularly well, even on other non-RPi machines I've tried. - GNOME Network Displays is close or essentially what I'm looking for, but lacks any meaningful documentation I can find Across the board they all seem to rely on WiFi-Direct support on the sink, but that too is coming up lacking in the RTFM-department . This protocol/stack seems somewhat ubiquitous, especially for embedded devices, but a total PITA on POSIX. The closest I've come to touch this end of the stack is around wpa_supplicant (& its associated wpa_cli & wpa_gui lower-level toolstools), but these are not yielding the results I'm looking for (such as the P2P config - PIBKAC) I do have a few spare Android mobiles I would flash, but this will introduce a whole host of additional complexities I'd rather like to avoid & I'm not sure this'll improve the situation. I'd appreciate any help that could be provided, as I'd like finish this off this build & put on the final touches.