You are correct total stoner broscience. Zero real science that supports flushing at harvest. Removing nutrients from the medium will just cause the plant to suck them out of the leaves and still direct them towards growing new buds. Growing healthy plants to full maturity, and then drying them slowly is what creates the best tasting, smelling, and smoking buds period. You don't need to cure anything or use fancy hygrometers or boveda packs. Those are all crutches to fix problems that only exist because you did something else wrong along the way(usually cutting early or drying to fast).
I've tried most of this stuff over the last 13 years. I stopped doing most after enough experiments to prove to me it was pointless wastes of time and energy. Let alone the money on extra stuff that was totally unneeded.
I havn't cured a single bud in years because once I learned to dry properly the weed never got any better, and it never lasted long enough. When people that have no clue I grew the weed are raving about it I think I did ok.