magnetic variation doesn't change all that quickly at 100 knots, and charts provide the variation. I don't really see it being a much bigger workload, and I ima

magnetic variation doesn't change all that quickly at 100 knots, and charts provide the variation. I don't really see it being a much bigger workload, and I imagine that if this change does occur chart plotters like Foreflight will start displaying the current variation very prominently for convenience (it's already pretty easy to pull up). I can also imagine people starting to sell retrofit bug rings for heading indicators that let you set the variation in for convenient setting. But in general most pilots of slow aircraft probably already know the approx. variation around their area by memory, most pilots of fast aircraft will have instruments that do it for them.