W2W does not provide a way to prevent employees from making schedule changes after a certain set time before their shift is scheduled to start.
Whatever permissions you set for employees – whether it is the ability to add/edit their own shifts at any time, or to trade or pick up shifts before they start, these are global settings.
5 days leading up to their shifts but have it open to changes to them every day outside that 5 day period leading up to the start of their shift
block changes to the schedule