according to the unintuitive mechanics guide (which the devs seem to have endorsed as correct), damage over time should leech. i have the “soul maw” node in lich, which gives damage leeched as health (not damage leeched as health on hit).
i’m using aura of decay, and have just enough health regen to sustain it, with barely any positive regen, making it very easy for me to monitor when i’m gaining health from leech. when i’m doing 5k+ dps to enemies with aura of decay, with 20% leech, i should be leeching 1,000 health per second. instead, my health continues to have just barely positive (a few points a second) regen.