“Another thing to note is that this hack was done on a modern Fluke 77 IV meter. If you have a Fluke 77 from 1985, this hack doesn’t apply”. So it sounds to me like they *have* just updated ...

Really tiny, like leakage currents through a capacitor. ... For example, on a Fluke 115 meter, [Danny] found that he could read up to 60nA with a resolution of 0.01nA.