I have been using PinPoint (& Visual Pinpoint) from DC-3 Dreams for some time now on Windows... it is a VERY fast solver... and using local catalog files (all the usual including UCAC4 now) can solve an image with rough RA/DEC in around 5 seconds! It does have the ability to all-sky solve using astrometry.net with the same sort of timing responses as Ekos...

PinPoint can be scripted with VB or similar to return various elements of a solved image given hint RA/Dec coords....

so, my request would be to be able to utilise a client local solver program, to be supplied with a fits (or maybe jpeg?) file, returning whatever required astrometry details.... (my example can echo the solve results to stdout, for e.g)

Phil