I know how orbital dynamics work with the absence of non-gravitational forces. But it's not a point that you suddenly stop interacting with the atmosphere, it'

I know how orbital dynamics work with the absence of non-gravitational forces. But it's not a point that you suddenly stop interacting with the atmosphere, it's a gradient, with asymmetric forces on the forwards and down directions from gravity/air resistance that are smeared over time, a bit like a non-instantaneous burn around the fast end of the ellipse; I'm not sure how well the "free motion in a vacuum" intuition holds in this case; but especially when your delta-v from the atmosphere is smeared nonlinearly over your ascent period. Yes, you end up at the same height or lower the next time round, and will incur drag from that, but shrug, that's just regular orbital dynamics.