hmm...

I do agree > 7 bit is not required for the majority of controls, probably only those which are used for direct performance, i.e. at your finger tips, hence why things like the Eigenharp support it. Even then most modern synths will smooth out controls for 7 bit, so its hardly noticeable.

but midi as a protocol (ignore transport for a moment), 14 bit midi vs a different 12 bit encoding is not going to as such feel worst/better, assuming the quality of components used are the same), and given a reasonable implementation no more likely to have 'accidental' transmission.

but there are many poor implementations of midi that introduce jitter, especially at 14 bit, often not helped by the USB or DIN 'transport' and the way PC handle it... (widely reported)

hopefully axoloti does not have this issue, since its running on an RTOS, and processes at a high priority.

pitchbend, sure on your 'average' keyboard, when doing a bend over a couple of semitones, 7 bit might be enough... but this is not the case when you start using with other controllers where the bend range is much larger, e.g. expressive controllers, theremins, midi guitars. e.g. the Haken Continuum for its full size has a 96 semitone slide, at 14 bit this is not enough resolution, so they use 21 bit. (an extra CC to supplement).

a bit of trivia, the Continuum uses midi internally between its keybed and sound engine (Eagen Matrix) and my (limited) experience with it and other musicians reports, is it 'butter' smooth

your 3khz is extremely high, the developers of the expressive controllers have obviously been very interested at what scan rates the musicians can feel..... most of them have settled on between 500-1000hZ and Ive not seen any complaints. though I will grant the Eigenharp has the highest at 2kHz and this is often reported as feeling the most 'alive' (but this likely due to many factors, given its unique design and software)

that all said, of course if you buy a midi controller of the shelf, its unlikely they will tell you what the scan rates are, so using your own pots/axoloti you bring this into your own control might feel better than many commercial controllers.