I knew if I spouted something about using a KD pattern that the smarties like Jeremy would come out with the process.
Hopefully the extra holes in the modified KD pattern (2 above and 2 below) will work.
With a "phantom shelf" adding the line boring, you would have to make sure the positioning was maintained (by also adjusting the "phantom" adjustable shelf) if the hybrid (fixed with KD) shelf depth changed. With the fixed shelf/KD solution, the related operations shift automatically since the pattern is all linked.
The only thing I can see as causing an issue will be that -
Since (if I am not mistaken) a fixed shelf defines a "opening", you will have to define the doors FIRST and then added these fixed/adjustable hybrid shelves afterwards.
** I think that we had suggested a while ago that perhaps an option could be made that
if a fixed shelf had a front inset, that
it would then NOT be considered as defining an opening. (Might be an idea for the 6.1 release???

)