Re: target knobs
Stony Point makes 'target knobs' for Leupold and Tasco (as I recall) that simply fit onto the existing adjustment hardware. They engage the coin slot, and enable you to grasp the knob and make adjustments without fumbling for change. Dealer cost is about $40/pair, retail perhaps $50/pair.
Available in at least a few places, Midway and Cabela's being two.
it's not about need in the USA -- it's about WANT