I didn't claim "macrodynamics", but dynamic range and of course I need to add increase of compression, which is inevitable if you force any transducer into more excursion. Since the driver is operating outside of it's optimal range, you may notice loss in accuracy. This has always been a problem with headphones. They use single drivers, which means that if you mess with the bass, you decrease fidelity in the upper range. There's no way around it. You will loose macrodynamics, as you called it, because every driver compresses the more, the further away it's pushed outside of it's mechanical center.

So to sum up, increase in nonlinearities from using EQ is inevitable, especially with boosting bass. This is especially propnounced in single driver headphones, because it affects broader range, including the region of highest hearing sensitivity. So using EQ is always a matter of tradeoffs and weighing desired and undesired audible outcome.I personally listen at low volume so I like EQ, any compression from it is not noticeable in regular use, but I can see how people can have issues with their equipment.