Processing options for the bevel include some settings for tailoring how the bevel is applied.
Freezes the azimuth (rotary) axis of the bevel, and sets Bevel Rotation Begins (and Ends) to be suitable for the start of the first cbevel segment after the leadin.
Leadin Anti-Rotation unchecks Bevel Rotation Auto on the leadin, sets Rotation angles automatically to suit start of first segment
If checked causes the torch to take up the initial bevel angle over the leadin segment, as opposed to piercing vertical and tipping over immediately:
Without Leadin Transition
With Leadin Transition
This is not a setting in the processing options, but can be set via bevel leadin properties. If checked, the torch will tip to the Bevel Angle Begins angle before piercing, ie it will generally pierce at an angle. If the tool uses initial height sensing it will do this with the torch vertical first, then tip over, then pierce.
CAUTION: piercing thick materials at an angle can cause a "rooster tail" of sparks and hot metal that can potentially cause burns to the operator or passers by. Orienting the azimuth consistently for the pierces so the rooster tail is away from the operator can mitigate this risk.