Is it possible now to search/query for activities by a given time duration in a given zone or minimum average heart rate? For instance, it would be very useful to be able to search for all activities where my average heart rate was within 5 bpm of my LTHR for at least 20 minutes. I like that intervals does LTHR detection, but getting able to review all activities that might constitute a best 20m effort would be helpful to dig into conditions or effects around each such activity (weather/heat, stress, diet, sleep, life events, etc.) and possibly manually adjust LTHR accordingly.
You can query for a given average or max heart rate, but not for something like a max 20 min average. This is something I have requested earlier. I think it would be very useful to search or sort by max HR, power or pace for some given duration. Imagine you want to find you top 10 efforts by looking at the max 20 or 60 min power.