System reserved partition (SRP) is full, needs cleaning

A couple years ago I was trying to get WIndows Backup & Restore working, but it wouldn't because the SRP was full. I found a way at the time that with a few commands (either in CMD window or Powershell) that quickly cleaned out this hidden garbage once you assigned a drive letter in Disk Management. Fixed the problem at the time.

Now Windows Update wants me to go to 2004. OK, I waited long enough. Failed quickly with little clue. Tried then with the 20H2 .iso, this time I got the message that the SRP is full. Win 10 Pro, running 1909. Only 4meg free on SRP, yet treesize says it is only half full (50mb). I cannot remember the commands that clean up this absurd mess. I'm not extending, recreating, because none of that should be necessary.

Anyone know the commands that fix this?

A screenshot of disk management would help immensely:
https://www.tenforums.com/tutorials/...%20it%20easily.

I'm familiar with it. The fonts take up very little space, no idea why MS posted that. No, as I recall, there was a list of a few, likely powershell commands, that were capable of cleaning out whatever this super-hidden garbage is. I've set folder options to show any hidden regular or system files, nothing. Treeesize says it's only using 50mb out of 100mb, yet only 4mb free. The commands I can't remember any more reset some file, I believe a log, that keeps growing out of control, yet is hidden where you can't see it. They nuke and recreate the hidden log at a normal size.

- - - Updated - - -

A side note. The recycle bin on SRP actually had recent files in it, photos from some scanning I was doing. Very odd, yes, I cleaned them out.

SRP is a true PITA!