Here is a new Gotek FW which is open source. It supports HFE format (developed by HxC) and will soon natively support .ST (I think they added Atari Floppy disk drive interface support from 0.6.1a)https://github.com/keirf/FlashFloppy
It is compatible with the HxCFE File selectorhttps://github.com/jfdelnero/HXCFE_file_selector
I would still recommend buying the excellent HxC Gotek FW
. The author of HxC has shown full commitment to many platforms over many years.
It would be a shame if everyone went to a free solution only for both authors to stop development.