I'm still struggling with this. I've tried 3 versions of epkowa with the same result on 3 kernels. The best result I get is with the epson backend where it will wait for the SCSI timeout then scan from the flatbed and be ready to do it again. Not a peep from the ADF.
The only anomaly I can see is scanimage -L is inconsistant. Sometimes it will detect the scanners but usually not. sane-find-scanner always finds them except after a failure with the ADF. Xsane will find them even when scanimage -L and iscan do not. I have a Nikon Coolscan III on the same SCSI bus as the GT10000. That works perfectly, as does the GT in flatbed mode. It occurs to me that there are two models of ADF available for the GT10000. Are they both supported? I have the duplex model no. B81321*(model EU-45). Martin