20H2 some how took me a few seconds to download and about two minutes to install and restart. Apparently it was an "Enablement Package" or something, I don't know if Aero Glass would break on it if BigMuscle releases a version for 20H1. 20H2 is only 1 build number ahead of 20H1 so hopefully it wouldn't break anything.
Windows always used to be the OS where you could do whatever you liked, theme the crap out of it and customize it to your liking. It's starting to become more like macOS where you can't do much and everything is the way Apple wants it to be.
Look on DeviantArt and there is a theme called "Aero 7", download it and put it in C:\Windows\Resources\Themes and then patch and apply it using SecureUXTheme.
Yes, I applied the Aero 7 theme to Windows 10 2004 using SecureUxTheme and it works OK. The rounded corners work ok and it has the glass effect but no transparency, some applications also look weird...
I am pretty new to using this software, right now I'm on Windows 10 2004 and I feel like it's taking a while. Has the developer been inactive or something because I don't remember it taking this long.