Yes, see above. When we looked at them, they were simply too expensive for the job. But JCPanosh did use such a bridge successfully.
Currently, we have upgraded our system from VMWare SCSI pass through (which tended to hang as previously explained) to a low cost headless and mostly diskless server which runs a minimal Linux installation and a script to buffer data before passing it to the SCSI tape in bursts of a few GB. Basically, we did a Virtual to Physical conversion to work around a VMWare bug.