There is a difference between a designed “uniformly distributed load” and “concentrated load”. What I would do if I were to encounter such scenario is I would find out what is the design minimum concentrated live load of the access to the staging area is. IMO, one simply can’t use a “uniformly distributed load” for such calculation, otherwise he/she would be crashing thru almost all of the floors simply by standing on one foot. :lol
I am not an engineer, and these are not advice. Just my opinion on an imaginary situation.