Porter customer service told me that even if you are checked into the airport in advance of the recommended time (30 minutes for YTZ) they will leave without you. They said their normal procedure is to make a call for the passenger but for me they did not. This is terrible service. I ended up having to take a 1-way with Air Canada which was much better service.
I took another flight with Porter and they did not do a boarding call for the 12:55pm flight it took another 40 minutes after boarding time, with all the passengers asking what's going on before they announce that the flight will be delayed until 1:55pm which then it still did not leave at 1:55pm, it left well after that. very poor communication.