I just upgraded my HTPC box with technodevotee's 64 bit WMC-13 from Windows pro 1909 to 2004. WMC broke,and running the fix_MSSQLLite.cmd andreplace_dlls.cmd scripts did not fix the problem, which was that WMC would just silently not start. I ended up having to reinstall WMC (maybe because there are some more of technodevotees tricks and scripts I didn't know about), and after some work everything is fine. Certainly this was not effortless like 1903 -> 1909 was. But in the end works great.
If there is a way to go from 1909 to 2004 without reinstalling, would be good to post the steps here. I don't personally need it, because I have already got it working, but it would be informative.
Of course it makes no sense to upgrade to the latest and greatest Windows if you don't have to, but I am a bit rash and compulsive and protect myself with robust backups.