Update 5.3 is scheduled to land for Rainbow Six: Siege today, and on the Ubisoft forums the patch notes give a little bit more detail about what players can expect, the first feature revolving around pausing in player-hosted custom games:
"We have added a Pause button to the UI that will allow the host of a Player-hosted custom games to pause the match during the Operator Selection phase," the notes read. "To utilise this functionality, the host will need to press [End]/[Start+DPAD UP] to stop the timer. Press the button again to resume the timer."
Along with this there's a whole host of bug fixes and tweaks, such as barricade pieces being stuck in place or an Operator's shield disappearing through clipping. Full patch notes can be checked here. Are you grateful for the new pause feature?