Organteq is a proof of concept of a bigger instrument that's going to be released sometime in 2018... as a plugin, as well. So, organ counterpart to Pianoteq - expect a lot of flexibility. :)
Already bought three of those and wound up not using them. I will try GG Audio Blue3 since you recommend it - never seen it before. Downloading the trial but unimpressed by the demo tracks. Maybe it the players but that green onions is painful.
I downloaded some packages from then took the SF2 files out of the packages and played them through so that I could duplicate the instrument for the different ranks of pipes. As a bonus, some of the packages include impulse responses of the churches where the organs are installed. It's a bit fiddly, but I got acceptable results.