A non-zero pause value in cut-through mode pauses the start of the movement even if cut-through isn’t enabled. Also, the same layer changed to fill from cut experiences the same behavior although the pause value isn’t visible and can’t be changed.
The pause on fill isn’t (and I believe has been fixed already). The pause on line mode even with Cut-Through disabled is intentional. The toggle is choosing whether or not to enable the beam - non-zero numbers in the start / end delay will always pause, though it didn’t always - this change was added in 0.9.10.