Next on the list was the Microsoft SyncToy program, which is NOT reported
to work with Windows 10, but which is reported to work on Windows 7 on
down.

I stored the executable in the installer hierarchy at
c:\installer\network\autosync\ms_synctoy\SyncToySe tupPackage_v21_x64

When run, up pops a license agreement for "MS Sync Framework 2.0 Core
Components", and then another license agreement for "MS Sync Framework 2.0
Provider Services" and then you have to check a box saying "I have read and
understand the warning notice" and then you have to agree to the Microsoft
Synctoy 2.1 license agreement.

It wants to install into C:\Program Files\SyncToy 2.1\
I put it in C:\app\network\autosync\ms_synctoy

After the installer ran, it just closed, without any evidence left.
I made a shortcut to the "SyncToy.exe" where the first thing it asked was
to participate in the "Customer Improve Program", which you can deny.

Up pops the SyncToy GUI where the only button available is
[Create New Folder Pair]

Microsoft also uses this terminology of "Left Folder" & "Right Folder",
which is strange, but I get what they mean (it's a source & destination).

You get to choose the Left Folder with a "Browse" button, which _does_ see
the MTP connected LGStylo3Plus (unlike SyncBack Free),

Drat. If you select a "Left Folder" on your PC, it doesn't gray out the
"OK" button, but if you select a "Left Folder" anywhere on the Android
device connected over MTP USB cable, the "OK" button is grayed out.

So again, unless you run FTP (to connect as a drive letter over WiFi), or
WebDAV (to connect as a drive letter over USB), you can't even _select_ the
Android device using the SyncToy GUI (AFAICT).

As usual, the immense cost of freeware is in all the testing to find the
best ones, where you really want someone else to do all that testing for
you, where this Microsoft SyncToy is a nice tool, if you had a drive
letter, but it doesn't work over MTP as far as I can tell.

At least the Microsoft SyncToy uninstalled gracefully, without any overt
phoning home.