That design you describe is what is pictured at the top of the article.
Problem is that then the keys are not equally spaced chromatically (e.g. larger spacing between B and C than between C and C#).
You could probably get used to play like that, but it would be ineficient in terms of space for both the fingers and the mechanics of the piano (hammers, strings).
So what you do, in reality, is move some of the black keys down a bit (C#, F#) and some up (Eb, Bb) so that the spacing between the center of the keys is regular.
I don't think that's what's described in the article though?
Problem is that then the keys are not equally spaced chromatically (e.g. larger spacing between B and C than between C and C#).
You could probably get used to play like that, but it would be ineficient in terms of space for both the fingers and the mechanics of the piano (hammers, strings).
So what you do, in reality, is move some of the black keys down a bit (C#, F#) and some up (Eb, Bb) so that the spacing between the center of the keys is regular.
I don't think that's what's described in the article though?