All equipment is "almost" perfectly compatible, but when it
comes to the bee space between frames in stacked supers
and brood chambers, this is where things start to fall apart.
The only "problem" caused by these incompatibilities is
bridge comb, which is easy enough to scrape off when you
find it. I try to avoid it by making my own boxes, and being
very picky about frame top-bar thicknesses when buying
frames.
In a worst-case scenario, one could stack a super with
"top space", and the bottoms of the frames even with
the bottom edge of the super, atop a super with "bottom
space", where the top surface of the top bars are even
with the top edge of the super, and crush a whole lot of
bees in doing so.
If you were to e-mail kim@beeculture.com, and ask for the
most recent "Woodenware Review" article, he'd send you
a rundown of exactly what frames are truly compatible with
what boxes, and what boxes, when stacked, can cause problems,
vendor by vendor.
The lack of standardization in the area of "bee space" is
a real travesty, but my attempts to get anyone interested in
forming a standards committee have not resulted in any
interest, as most beekeepers simply accept being "locked in"
to a single vendor, or ignore the problems.