Here is the current situation from a tech geek's point of view. United's direct streaming system for web browsers is inherintly broken due to relying outdated DRM software and the dev team focussing entirely on getting it to work on mobile devices, IOS and Android. (For instance last time I flew to denver, it wanted me to install flash .....)
Though if you have windows 11 device, you could in theory do the following steps and it might work.
1. Search for advanced start up, and hit restart now. Navigate to BIOS option.
2. Once in BIOS enable virtualization
3. save changes and restart
4. Open the microsoft app store, and download the Amazon app store app.
5. This requires two reboots for it to install properly.
6. Install the united app.
7. Log in, and congrats your laptop now counts as a bording pass.
8. IN THEORY, you might MIGHT, be able to get private screen to work on united app running on your computer.
So I have yet to test this setup, since I am not a frequent flyer and just like to lurk on here. But i did setup it on my father's personal computer and he is supposed to fly this coming week and is going to try it out.