Normally I get Android to work before even attempting iOS simply because
Android is always easier.

Unfortunately, in this case, the only program that worked with Android over
MPT on USB without having to assign a drive letter was the sophomorically
written GoodSync free, version 10.9.32.2
o *GoodSync Free*
https://www.goodsync.com/download/GoodSync-v10-Setup.exe
https://www.goodsync.com/download/GoodSync-v10-2Go-Setup.exe

I disconnected the network and tried to install it again, where the
software was archived in
C:\installer\network\autosync\goodsync\GoodSync-v10-Setup.exe

Being off the net, GoodSync asks to "Configure GoodSync Account",
where it says to "Register this computer with your GoodSync Account", where
there are only three choices:
(o)Setup GoodSync Account later
(_)Use my existing GoodSync Account
(_)Create a new GoodSync Account
This finishes the installer.

The good news is that I don't have to set up a GoodSync account, which is
what I would have expected - but we'll see what happens when we go back on
the network.

Still offline, running the GoodSync program, and after turning off the
automatic updates, we get to the "Enter Job Name" form and the "Select Job
type" radio dial.
(o)Backup
(_)Synchronize

On the top of the GUI I click the left folder of the two folders to set the
"Media Devices MTP" source connection to the USB-connected LGStylo3Plus
icon, SD Card, test1 folder.
mtp://LGStylo3Plus/SD card/test1

Then I click the right folder o set the C:\tmp\test1 destination directory.
I then click "Analyze" and then "Sync".
file:///C:/tmp/test1

What's strange is that it hung and had to be killed.
Huh?

Still off the net, I tried again, and it worked the second time, copying
over a file that I had added to the test1 folder on the SD Card from the
Android side of things.

Then I copied over another file to the Android SD Card test1 folder, and
then connected the PC to the net, and tried again.

Back on the net, with VPN running, I clicked the "Analyze" and "Sync"
buttons, which copied over that additional file from the USB connected MTP
Android SD card folder to the PC.

I then set the GoodStart GUI to perform that task automatically, where
there is an "Auto" button the top right which provides the following
options:
[_]On File Change, Delay = [0] sec.
[_]On Folders Connect
[x]On GoodSync start
[_]Periodically (On Timer), every [2]hour [0]min
[_]On Logoff
[_]On Schedule [Configure]
Run here in GUI or in Runner Service
[_]Run without User Interface (Unattended)
Advanced Auto options
[_]Do not Sync if changed files more than [100]%
[x]Wait for Locks to clear, minutes [0]
Automatically resolve conflicts (choice of)
- Do Not Copy
- Left Side Wins
- Right Side Wins
- Newer Files Win
- Stop Sync
[_]Conflict Resolution: Rename Losing File, not Delete
[_]Auto Clear the tree after Analyze/Sync has finished
[Save]

In summary, of all the tested programs, only GoodSync freeware seemed to
"understand" the MTP-connected Android filesysem on USB, although some of
the others "saw" the MTP device, but they wouldn't accept it for file
transfer.

There are _many_ options, and even scripts that the GoodSync freeware
handles, where my main complaints about the freeware are things that others
may not care about - so it's a good program, I think, for others to test
out.

I did try to have GoodSync automatically run when a file is changed on the
Android device, by setting up this option:
[x]On File Change, Delay = [0] sec.
But that gave me the error:
File Monitoring not available on: mtp://LGStylo3Plus/SD card/test1
so that type of automatic sync failed.

However, the automatic sync worked when I restarted the program due to the
setting:
[x]On GoodSync start

My main complaints with the GoodSync freeware are minor for most people:
1. If you're on the net, it seems to ask for too much login information,
2. It doesn't respect basic coding standards