Mike Filip
Ok - I will agree with you here. Having the keys not be an ordered set does allow one to 'locate' themselves on the keyboard better if they are not capable of looking at the keyboard (ex: sight reading). I am not sure how important this is, but this is a positive on the side of the classical keyboard.
I am going to hold out that visually, the fact that the Janko layout keeps the diatonic coloring of the notes (7 white and 5 black keys in the C major pattern) it provides as good as a classical piano layout for orientation (though once again - only visually).
One thing that you mentioned in the previous thread that we cant overlook though is the 'back of the black keys' being used for alignment - to the point that removing them along the backs of the keys is detrimental.
This is a very good point and something I went to my piano and tested just now - played a few pieces and just focused on how I place my fingers. So… yea - I use the sides of the black keys to sort of lean or perhaps hold my fingers against in order to help with alignment on the keys. How much of a detriment not having the ability (or necessity?) of playing between the keys (white between black) on a Janko piano is to be seen.
I went back to look at photos and videos of the acoustic Janko pianos and a few of them had very dome-like keys (more like a cylinder dropped on its side, with the axis facing forward). I did round out the corners of the keys of my DIY piano, so maybe that would help with alignment; if not I can also try a fully rounded keys more akin to the original Janko piano, but it might turn out that having that option / necessity of playing between the black keys is actually a boon for the classical piano instead of a disadvantage I initially saw it as (ie: there are a couple passages in the pieces I play which are a bit uncomfortable due to playing mostly on the whites between blacks)
On the other hand, playing on the Janko keys should feel more akin to playing with only the black keys on the classical piano - there is no 'alignment' to be done outside of 'feeling' that you are centered on the key. Guess only trying it out will solve this question.