So the other thing to consider that's often overlooked is what nozzle you're using. If you're using a steel/hardened/nozzle-x or similar, you will measurably compromise the energy transfer to your filament. If this is the case, it's entirely reasonable to need a temperature 10degrees or more than what's quoted for your filament.
I use an Olsson Ruby nozzle which is another special case. The body of the nozzle is made of two parts, so despite it being a brass nozzle I print pretty much all PLA at 210/215 degrees and can't achieve higher volumetric flow rates without a lot of fine tuning.