I think all scopes should be first focal plane. Having said that, almost none are first focal plane and that annoys me. Ballistic reticles that only work on the highest power when I am trying to shoot in light conditions that prohibit using the highest power just seem foolish to me.
Calculate your own, for each magnification setting.
Every manufacturer that I have checked into has their reticle subtensions published for each magnification step in the scope.
I've calculated hold points for almost every scope I own, based on the most frequently used loads for those rifles. All it took was some decent "real world" velocity data, the reticle subtension figures, and 5-20 minutes of my time.
Or... do some research next time, before you buy the scope.
Calculate your own, for each magnification setting.
All you need are the subtensions of the reticle at the magnification settings that you're interested in and the ballistics of the load, to calculate for 'hold over' points. It only takes a couple minutes (if that) to do the math for multiple ranges.That’s a lot to keep up with! Sitting at a bench with a calculator and all day to shoot, using a multiplier would probably work. Otherwise, you're better off shooting at high power (if you can) or changing mag after ranging.