@brad_olwin gotcha. Sorry for my attitude - I simply find it shocking as I regard Suunto as a company who treats UI/UX very seriously and this example is just plain bad for the unsuspecting user.
Anyway, here’s my rather simple solution with some assumptions:
We’re not modifying ETA algorithms or doing any “deep” work.
ETA fields can’t force 1s GPS out of the blue.
Here’s the course of action:
Enter the workout screen.
Check if workout has ETA fields present.
Check if workout has a battery mode that sets GPS to other than 1s.
If two above are true, wait for 1 - 3 seconds and display what follows:
suunto-mockup.png
The above mockup is relevant to a situation when user has selected (or has used before) an “Endurance” battery mode but the bottom part should display “Ultra” or “Custom” with appropriate colors when appriopriate.
Why wait for 1 - 3 seconds?
This message should be triggered when conditions are met and should prevent starting the activity. However - users may want to cycle the battery modes with upper button until they reach their preferred one, so a delay is necessary to avoid displaying the same message for Endurance, and then for Ultra and then for Tour and for Custom - you get the idea.
The information is there, the choice is to be made
We have a simple info that in order to see the ETA the watch needs a different battery mode than selected by the user.
The difference it makes
You can switch to “Performance” (or modify your custom battery mode to 1s GPS) and get your ETA fields working AND get accurate battery life estimation pre-workout. Or you can use different battery modes without ETA fields enforcing 1s fix but see “–” instead of an actual data.