"too low" + "too high" power alerts in custom made bike workouts.

Hi all,

I'm a bit confused as to why there's no apparent way to engage a "power too low" or "power too high" alert specifically to custom workouts.

This feature is available for the ride generally, but not for specific training when you'd like to be in certain zones for certain periods of time.

What is available strikes me as ridiculous. It'll indicate when I'm "in the desired zone"! This means I'll need to be paying way too much attention to the device instead of the road to ensure I'm in the correct zone and an alert will only sound once I've recognized this and adjusted my power output to match.

I have an Edge 520, Forerunner 920 XT and a Fenix 6, but just because I have three devices doesn't mean I'm particularly nimble around technology.

I'll post the same  question in a page that matches the other 2 devices, but if anyone can suggest how to sort this with the Edge 520, it'd be really appreciated!

Thanks,

Paul