I have place bound to left click (default), and pipette bound to ctrl-click.
If I have e.g. a east belt on the ground and am holding a north belt, then ctrl-clicking the east belt will replace it with a north belt (changing its rotation as well as clearing it) as well as the expected outcome of setting my held item to east belt. This seems to only happen if I'm ctrl-clicking a belt, not any other structures
(Since this doesn't happen if pipette is bound to a key, I'm assuming this isn't intended)