Loren Coe wrote:

i hope the hell not. i possibly overstated the intended load, that one
33-34" section was pretty much the max, and not typical. the 40" section
was probably unique, against a plumbing wall, which actually speaks to
your point.

Hopefully it isn't also a bearing wall that is holding up a lot of
vertical live and dead weight load. If the shelf pulls the wall out
of vertical with the plumbing notches in wrong the side of the stud,
it can collapse in buckling mode due to induced eccentricity with,
maybe, a few milliseconds warning. Buckling is a truly nasty failure
mode.

I don't know what the wall's role is in the structure, so this may all
be worrying about nothing.

Since I've been doing a lot of structural calculations to firm up this
house design, I've gotten a whole new respect for their structural
integrity, and, possibly more importantly, how it can be screwed up.
The traditional framed house is a really forgiving structure, most of
the time ...

Fitch