It should have been the 720k version, I know, but that was the only model available at the local importer. Seeing that you need to adapt the 26 pins to 34, just like with the 1.44 floppy drives that reportedly work with the SY, I thought I´d give it a shot.
I didn´t use an adapter BTW, having instead desoldered the 34 pin and the power connector and soldering directly the 26 pin cable from the SY to the Gotek´s PCB. I believe I got the connections right, but if someone knows of any shortcomings, please advice.
I also tried different jumper combinations, several thumbdrives, several formats. Nothing worked. Even pressing both buttons at startup for the auto-format feature. It did autoformat the thumbdrive, but the SY kept saying "bad disk".
On the FlashFloppy site it´s said the only difference between the 1.44 model and the 720k Gotek models is in the firmware, and that the FlashFloppy firmware is the same for both models, so I flashed it in according to these instructions:
It´s apparently working as it should, as it even lets me update the firmware via USB thumbdrive only.
But the error E34 keeps appearing

Any thoughts?