Rule clarification: Size of the beam/leverl

[boutanit]

Hi-
The first rule was repeated many times:
Ensure device fits into the bound box, 1m x 1m x 0.5m
But then I recently notice this second rule in the slides:
Ensure Division B Beam is less than 80cm no matter how measured (include anything on the ends)
Is the beam = "lever end to end" or "from fulcrum to end"?
I am pretty sure it is the former, but it means we have to redo our lever, so I wanted to double check.
If the beam = lever end to end, then the box seems overdimensioned. I understand people can go crazy with the support etc...