Never used POA, it’s there as a cop out to appease the likes of RDCs instead of getting them to pull their fingers out and get their acts together, so that we look as if we are working reasonable hours…a la WTD (another load of ■■■■■■■■) when we ain’t really. 
So any waiting time it’s other work or break.
As for break deductions I only get 45 mins taken off however much time I show.
O/p as you’re a new driver,.see what your employer’s take is on it…don’t take any notice of a seasoned cynical bast like me. 