ok - the linux machine worked - performance was much, much better than on the windows server 2012 instance. however, something was really messed up with my locale - although in the shell my keyboard worked perfectly, inside pixinsight the keyboard mapping was completely crazy... no idea what language it thought i was running but everything was gibberish. i was running ubuntu 16; somehow i was not able to establish the normal desktop environment in Xvnc. i also had to install the gstreamer 0.1 libraries.
i guess i'll try a fedora distro and see what happens.
on osx, control-S removes the STF. is it possible to cause windows and linux to use that same shortcut? (it seems to be set to F12 or control-F12 on those platforms.)
rob