Beautiful piece, and you played that complex thing very good! Some small slips (or "tiny frays" as you call it) but really no big deal.
Why don't you like the sound of that organ as it is? To me, it sounded very good, full and rich registration.
Actually, for all it sounding complex, this is a lot easier than that previous short Kyrie I submitted.
It's not that I do not like this sound, it is adequate, but a grand piece like this it can sound so much more majestic with a proper big Baroque organ in a more resonant ambiance.
Maybe it is easier to draw or footswitch a couple for two manuals in the coda instead pulling several stops? The coda was not slow in coming, instead it makes sense to breath a bit here. Just right!
I have no footstops on this organ, and I had most of manual 2 coupled onto manual 1 already.
In the coda, all
pipes sound, except for Unda Maris and Tremolo which I never use (amazing the wind machine can take that strain). I now have to first toggle the Krummhorn button (which is the right side) with my LH, while RH takes double duty for a quarter bar, and 2 bars later simultaneously toggle 16ft Prestant and Nasard (which are on the left side) with my RH, while LH takes double duty. Bit of a contortionists' act, and I was surprised to get it done at all without too much disturbance.
I could make it easy on myself by pushing the 'Tutti' knee button on the front, never mind these two extra registers. But all this would not be possible on a mechanical transmission organ unless I had someone to help (I think most organists have a registration assistant when concertizing or recording).