Always always know exactly how you will be paid, whether its salary or hourly or bonuses or a mixture of all and what deductions are made for breaks etc, mostly be careful if on salary you don’t make yourself work more hours than needed because you use POA or excess use of breaks for queuing time at drops etc.
Planners office bods TMs generally won’t tell you the nitty gritty for your benefit, they only tell you what benefits them unless you work for a proper company (often unionised) with decent terms.
Some companies don’t recognise POA at all, if you use it will be read as other work.