You can use Organteq to create a smaller sounding registration--without even reconfiguring everything. I would recommend removing/not using all 16' stops and limiting your organ to 8-12 stops consisting of more mellow-sounding pipes. You can also create more of a feel of a small organ by decreasing the reverb slider which will make the sound feel closer to you as you play--as it would with a small organ.
Your question is a good one. It's quite typical for any cathedral to have a large main pipe organ and a much smaller choir organ, and you can recreate the feel of either with Organteq, it just defaults to the larger sound.
Spotify:
https://open.spotify.com/artist/2xHiPcCsm29R12HX4eXd4JPianoteq Pro & Organteq 2
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Casio GP300