I found the following excellent library for copying files to and fro from my AlphasSync Neo2. However, I had to build it in Xcode from a specific pull request to get it working on Catalina.
Knowing that this is beyond the ability of most folks, I am uploading the app, so that other can benefit. I have simply repackaged it.
You can read about it here. Distributed under this license, no warranty expressed or implied.
You'll need to drag these files into Applications, and then go to System Preferences -> Security after attempting to run and allow these unsigned apps to run.