Not really. Nicotine vaporizers are meant to deliver the active ingredient (nicotine) without the harmful delivery method of inhaling burning leaves and all the tars, particulates, carbon monoxide, and other stuff that comes with inhaling smoke.

Kratom is more of a thing that tickles the right receptors enough to stave off opiate withdrawals (or stand in as a less potent agonist of those receptors with fewer side effects) so it's less about a safer delivery method and more like a "light" version of more potent opioids.