They’ll have to get a new SAS controller unless the RAID controller has an HBA mode. Running ZFS under a RAID controller is the best way to lose all of your data.
ZFS is wonderful but it takes quite a bit of planning and specialized knowledge to implement properly. Your fear of a failed RAID controller is a bit much, too. I’ve had to deal with a single controller failure in 30 years of IT (and I’ve done warranty work for all of the major OEMs in corporate IT for most of those 30 years)
CD Projekt is very much a software dev. I’m not sure why you would think they are not.