A half-press on the Canon RS-80N3 behaves the same as a half-press on the camera’s shutter button. It does not have separate autofocus behavior of its own.

So if your camera is set up for back-button AF and shutter half-press AF is disabled, a half-press on the remote should also not trigger autofocus. The remote is effectively just duplicating the shutter button’s half-press and full-press actions.

In practice, that means for timelapse or manual bracketing, the remote should not disturb focus just because you half-press it. You generally would not need to switch the lens to MF solely for that reason, assuming your camera’s AF is already decoupled from the shutter button.