BTW, I recently learned that the GPS system began as a clever hack by JHU APL engineers, who determined the orbit of the original Russian Sputnik satellite by listening to its Doppler shift (this technique was recently used to locate flight MH370 by measuring the Doppler shift of its telemetry signal). After doing that, they realized that this calculation can be reversed: geographic coordinates could be obtained by lmeasuring signals from a constellation of satellites in known orbits.
No, they didn't confuse it with a vegetable---apparently Zimerman recently modified his instrument and the piano smelled of glue. As a result he ended up travelling with just the mechanism, fitting it by hand to the boxes at concert halls he plays in.
A flexible TeX based system would re-run TeX when the layout changes. Can it be done quickly enough with modern technology? probably yes. Is it worth the trouble? I think the market has spoken and the perceived improvement was not enough to justify the trouble.