I work on sandy and variable soils and appreciate your points here very much.

At one time I grew some plants to use as indicators (eg. Butterfly peas to see if soil in certain areas is acidic or good enough for planting other plants; bougainvillea to see moisture in ground and and pineapples to see moisture in air; green mustards to see if the soil is "fertile enough";...) I also learned to use mulch and micro-biota more to improve soils. But after a few years (and a few acres) these days I choose what can grow well rather than what can change soils ;-)