As an engineer, accuracy is something I think about. However, one has to ask the question, "What is the reference standard for power meter accuracy?" I.e., is the meter on your bike 100% accurate? Is the trainer meter 100% accurate? Are either accurate? Is there a gold-plated set of power-meter-equipped crank arms locked in a vault in a secret location in France that define the standard for accuracy that all other power meters are compared against?
I'm of the (unpopular) opinion that as long as the power meter's measurements are remotely close to everyone else's and consistent with it's own readings over time, that's all one can really hope for.
Sorry to not answer your question and probably just make you more confused
