Many moons ago, when I was experimenting with developing my own, better-but-much-cheaper SuperThrive (abandoned, due to EPA regs), I began using humic acid as an additive to the formulation.
I am quite certain of its benefit in soils, as it helps release otherwise-sequestered nutrients, but I questioned its applicability to orchid-growing.
I know this is quite unscientific, but about 4 months ago - just before the time I had to start mostly "ignoring" my collection due to the various surgeries I endured - I added a liquid humic acid concentrate to my fertilizer feed tank, so have been feeding with it (it ends up being about a teaspoon per gallon), and it "looks" like it may be a "plus" after all, as I am seeing more growth and blooms than I had been (again I'll state - it's quite an unscientific assessment).
Anyone else have any thoughts or experience?