Years ago I had a small router plane with a screw adjustment that controlled the depth of cut. It’s been long gone (hopefully in somebody else’s toolbox), and I replaced it with one of the small Stanley 271s. A useful little tool — I use it a lot for flattening the mortises for mouthpieces in wooden planes — but annoyingly difficult to adjust depthwise. You loosen the screw and unless you are holding the iron you loose any reference to how deeply it was just set, which makes resetting at a slightly deeper setting very hit-or-miss. Suddenly, after years of frustration doing it this way, I realised that loosening the screw with the underside of the cutting edge resting against the edge of the plane’s mouth both prevents the iron from falling and allows me to deepen the setting with absolute control. Duh! How much longer am I going to have to live to figure out all these little details? Or is this the fun of the whole thing?