Your terminology is strange, you are asking for advice for a
friend of a future UPS driver. . .
Is that actually your question rather than advise for the future driver?
What type of advice are you looking for if so?
This hiring is certainly for seasonal use only.
However, if he shines it would make it likely that they would strongly consider him as their next permanent street hire.
Unless (and probably even if) he is in great physical condition his thigh muscles (and several other places) are going to be protesting after the first day by himself if he is in an older truck with the non-power steering and high step entrance/exit.
My Christmas helpers (jumpers was the more accurate term back then) were always close to worthless on day two from soreness, but the young bounce back quickly.