I have developed a solution of sharing a Windows Scanner via the eSCL protocol. It is called Twain2AirScan. Although it is compatible with SANE as a client via the SANE-AirScan back-end (not SANE-eSCL) ,it is not really "SANE" .
Recently I added duplex ADF where before it had only simple ADF. Unfortunately I have no Duplex ADF scanner. So I thought this group might be a good place to look for anyone with DUPLEX ADF Scanner that works on on WIndows that can help test this newest version. You can test with a Linux, Android or macOS client, while using a Windows Machine as a host. In particular I need to test Duplex ADF (scanning both sides) so you would need a duplex ADF scanner. You can find the download at http://scannershare.com its Called Twain2AirScan Thanks Mark