Intermittent white smoke in exhaust, but only under very hard acceleration

[00Shabadu]

We live in the Blue Ridge mountains, so naturally we have to climb large hills. My issue started 2 weeks ago. While climbing a hill on the interstate, trying to pass a semi, AT downshifted and was spinning around 4500rpm. All of a sudden, I’m throwing a James Bond level smoke screen. I’m thinking I blew the head gasket. Pull it over, get down to idle, the smoke stops. Pop the hood, have the wife hit the gas, puff of white smoke. Back to idle, no smoke. Start babying it to the exit to find a garage, and the smoke stops entirely. Make it home, no noticeable mixing of oil and coolant, no leaking signs. No consumption of liquids in oil, coolant, or tranny. Tried to replicate it around my neighborhood, couldn’t do it again at low speeds. No codes. Two weeks later, while climbing another large hill on interstate, it starts again. The smoke doesn’t smell like anything but exhaust. Any ideas?