It would be nice if Organteq had some options to ignore certain classes of midi messages as well (if it's already possible, I didn't find out how yet).

As I'm used to do with Pianoteq, I launch Organteq standalone, chose a preset and start playing.
I thus improvise a sequence of short phrases, changing the combinations on the fly.
Playing back inside Organteq works fine.
As I need to do some editing, I open Reaper with Organteq as VSTi, import my MIDI files into the track and start editing.
Then I realize that every time I restart playback of the sequence I'm working on the sound changes, it's no longer the same stops, everything is turned upside down and my MIDI is out of whack.
I finally understand that Organteq VSTi takes Reaper keyboard commands as Organteq shortcuts. For example, the space bar that controls Reaper playback also changes combinations in Organteq.
So don't forget to go into the Organteq-VSTi options and disable the shortcuts !

It is also recommended to take a look at the MIDI mapping.
The note events outside the keyboard area used for organ playing, which are intended for calling up the 10 combinations, can lead to irritating reactions if you use Organteq as a VSTi and the DAW track contains corresponding notes.