Ok, sad to see. But if I can drum up a few extra dollars I guess I'll try to donate at some point, but sorry, Social Security barely pays my rent.
So, for now, I will just uninstall.

This is all I got, there are two locations for Explorer.exe
C:\Windows\SysWOW64

and
C:\Windows\WinSxS\wow64_microsoft-windows-explorer_31bf3856ad364e35_10.0.19013.1_none_121ccf404d609610
Not sure why?
ANyway here is the screenshot of both with the same number.

Bummer on the Registry :(
The pinned icon space taskbar reduction is awesome and it's hard not to have it  LOL
7++ is 5.8
explorer as I can see is 10.0.180131

Yep, guess what... MS update killed it again.
(107) this time and the old tweaker doesn't work now either.
What is the RegEdit for eliminating the pinned icon space on the taskbar????

I luckily had the previous version

5.71.0 (I believe) and all is back to normal. 

It would be nice to have a few earlier version avaliable for download on the site. (all installation files are named the same so there's no way to know which was which, but I lucked out and still had the earlier installer - - of course it keeps telling me that an update is available)