@Craig I have relaxed regarding the overstated capacity claims lately. I realized that most people scan their film which means the raw scans are fed into automatic color inversion tools like NLP that perform far more invasive manipulations with color than a partially exhausted developer would. Essentially you'll get more or less the same image out of NLP regardless whether you're working with roll #1 or roll #40.
But... I am rarely happy with the default output of NLP, and plenty of folks here would agree. So I have no choice but to invert manually, and this is where minor deviations from the spec become really noticeable (and really annoying). Having acquired a color densitometer and a box of control strips, I started to notice how much easier it is to hand-invert negatives that were developed right on the money, i.e. within action limits. And needless to say that hand-inverting negatives outside of action limits is harder, and if you're outside of control limits it's a nightmare.
TLDR: reusing developer is fine if you're OK with auto-color.