SOLVED (so far) but a _better_ solution is requested so that everyone has a
general purpose solution that is powerful, and easy to use.

The huge expense of freeware is in finding the best programs, where I
tested the following five purported automatic sync solutions just now:

THIS WORKED WITH ANDROID ON USB AS MTP:
o *GoodSync Free*
https://www.goodsync.com/download/GoodSync-v10-Setup.exe

THESE FAILED WITH ANDROID ON USB AS MTP:
o *SyncBack Free*
https://www.2brightsparks.com/assets/software/SyncBack_Setup.exe
o *Microsoft SyncToy 2.1*
https://download.microsoft.com/download/6/c/4/6c406239-a648-4e01-833e-2c452deed3b6/SyncToySetupPackage_v21_x64.exe
o *Resilio Sync (free?)*
https://download-cdn.resilio.com/stable/windows64/Resilio-Sync_x64.exe
o *DSynchronize Freeware*
http://dimiodati.altervista.org/zip/dsynchronize.zip

GoodSync is imperfect - but it was the only one that worked over USB on
MTP, so, it's the new starting point for Android users.

First I'll get used to the best settings to use for Android automatic
copying of files and then I'll work on synchronizing both ways for critical
files such as:
o contacts.vcf (your contacts)
o passwd.kdbx (your encrypted passwords)
o calendar.ics (your calendar)
o container.hc (encrypted containers)
etc.

I'll test iOS later as iOS is always harder for almost everything.

If anyone has a _better_ solution for free automatic syncing of Android
file systems with Windows, please let us know what you use for that task.