Have you met an organist, who thinks that unless an organ has 3 manuals and pedals, it's not worth their attention?
There are many people like that, actually. When they sit down at the simple one manual organ, they don't know what to play.
"You can't play Reger on it", they say.
Which is correct, if you try to find an organ suited for your own needs and repertoire.
But what if the opposite is actually more true?
What if we need to find a repertoire that suits the organ?
This attitude would change things around, wouldn't it?
So if you sit on the bench of one manual instrument, think about how many stops does it have.
Let's say it has 8 stops. In reality, it could give you 64 different combinations of colors (8 x 8 = 64). Some of them more unusual than others for sure.
If you play just one minute on each stop or combination, you would need 64 minutes.
A hymn with 64 variations?
Or 8 hymns with 8 variations each?
That's plenty for an entire recital.