I have a complication that may need to update every 5 minutes. this could easily sum up to 120 updates per day. Is there a way to only update when the user wake up the watch?
I belief the answer to your question in NO, there is currently no way to only update the complication when the user wakes up the watch.
The reasons:
The idea of a complication is that the user sees it as soon as he or she raises the watch and activates the display.
There is simply no time to activate or launch an app, nor to download a real-time value to display it as a complication.
Thus, the data must be present before the user watches the watch face with the complication.
In many cases, this can be ensured, if the data don’t change too often:
On watchOS, it is possible to schedule background tasks at certain intervals that download actual data from a server. In your case, you would like to schedule regularly (in your case about every 5 min) a WKApplicationRefreshBackgroundTask to download the actual value, but due to power consumption reasons, the number of tasks is limited:
Background app refresh tasks are budgeted. In general, the system performs approximately one task per hour for each app in the dock (including the most recently used app). This budget is shared among all apps on the dock. The system performs multiple tasks an hour for each app with a complication on the active watch face. This budget is shared among all complications on the watch face. After you exhaust the budget, the system delays your requests until more time becomes available.
So there is no way to do this at rate of 1 per 5 min on watchOS.
One could try to do this via iOS, and send the new complication data using func transferCurrentComplicationUserInfo(_ userInfo: [String : Any] = [:]) -> WCSessionUserInfoTransfer, but the docs say:
If the complication is on the active watch face, you are given 50 transfers a day.
So I do not see any way to preload complication data at this rate before a user raises the watch.