Save Magnification Setting

I often edit on my MacBook Pro, and the main tool for navigation and correction is the trackpad. I like to edit blemishes and dust at 150%, but my magnification tool as I navigate aroud my image will flit back to either 100 or 200, which I then have to manually adjust using the trackpad, again. Step and repeat.

Please allow custom magnifications much as you do with aspect ratios or a checkbox to lock a magnification once achieved.