Hi Paul,
you are not the only weirdo on here – I use mainly Macs and also a couple of Raspberry Pis with Linux – and i’ve dabbled with other Linuxes in the past.
For convenience, though, I do use Mac version of MS Office…
Maybe you looked at the ImageJ photometry tutorial currently on the front-page – ImageJ is cross-platform and should run well on Linux/MacOS.
But sorry not able to provide much in the way of practical help on any VSS questions. But you certainly have my moral support!
Clear skies,
Callum