Has it been consider to add a possibility to show heart rate zones as colored information in the heart rate plot? Either as a background color for the different zone bands, or as color graded plot line a bit similar to the cadence plot. The idea is to easier see which part of the graph that is in different zones.
And further, is it considered a feature to show color graded track lines in the map, to present either pace, pace zones, heart rate, heart rate zone, elevation and so on as color grade? This way you could more easily read from the map where you push or relax etc. The information is already available by manually tracking plots and maps, so feature like this would be a "nice to have"-addon to easier read the information.