For this given site below we can compare the actual time to outcome (experienced by patients) against our estimates (50th percentile and 90th percentile). We see that the estimates only start recently, while we have been receiving data for quite a while.
Outcome wait time estimates can be configured 7 days after the outcome triggers have been implemented and provided everything looks in order, are turned on then so they are ready for go-live.
The above site example had their outcomes configured on October 21st and the wait time model configuration was ticketed for just over a week later.
One thing I'd like to add is that we will have some wait time estimating model that need 4 months historical data. So the wait time estimates using such model may need to be turned on only after the step triggers have been configured for 4 month.