Battle Royale Experiments
Battle royale experiments have occurred in the Zircon engine lately.
AI Upscale
AI upscaling has been an invaluable tool for helping older games like Quake put a facelift on the original skins and textures.
The Zircon engine download contains optional monster skin pk3 files that have been AI upscaled.
There are ways to upscale skins and textures online. These sites typically let you do 10 images free otherwise you must subscribe for $xx per month if you wish to do more than that.
Open Source Desktop App
There is an open source desktop app that allows you to use your desktop to perform AI Upscaling.
This application is called "Real ESRGAN GUI" and as the name implies has a graphical user interface.
It is being used right now to convert the shareware levels of Quake 1 into Quake 3 map format as a thought experiment. It is hoped to make these available this weekend.