First off I doubt I'm any smarter than you so I hope you don't mind me putting in my 2¢.
I don't have a perfectly consistent release.
Sometimes I pluck it a bit.
Anyway, I've played around with quite a few feather length, height, and number of feathers combos.
I found without any doubt after a lot of testing the larger the feather surface the less my arrow would wander when I purposely made a bad release.
Those extra feathers just "absorbed" more human error.
Also, having more (read higher) feather closer to the nock end of the arrow gives the fletch more leverage to do it's job. I know, I know that's nit picky but why not be?
Right now I'm shooting 4-4.5" with full size height T-Hawk.
Next time I might go a little longer on the feather....I was running out of feathers at that point.
I chose the t-hawk because it has the height in the back rather than the middle, but still the feather tapers down nicely in the back which helps keep the noise down a bit.
Good luck to you!
...btw..I do like the looks of what you're doing.