Are there any reliable apps on iOS where you can say playback a 4K recorded video and cast onto a PC (monitor is bigger)?
That sounds like your trying to push the physical limits of wireless technology.
Samsung you can use smart switch to cast your entire device to your PC.
Id be interested. My mum wants that capability. Also to cast an iPhone to a VW MK7 Golf MMI would be amazing.
Are you wanting to play the video in true 4K?
If it is just recorded video you want to show, the easiest way is to grab one of the various "Airplay" clients for the PC
and use the built in airplay on the phone...
I use Reflector 2 on occasion. It is a decent solution but not without its drawbacks such as the occasional glitch with audio and video. It can emit some loud and high frequency (very brief) noises which I fear at times may not be so good for my speakers.
Just a reminder that there is a Lightning to HDMI adapter available, which may be more reliable.
I heard it barely does 1080p so I am guessing it will never do 4K
Involuntary autocorrect in operation on mobile device. Apologies in advance.