Show on chart, zoom, scroll > Position is lost
if I pick a position on a long track, eg at 20 km on a 300 km track, and go "show on chart", the position is indicated in the chart showing the full 300 km.
The "+" button zooms to the middle of the chart, eg km 150. If I scroll (swipe) through the chart, after a few swipes, a new position is picked and the one that I wanted to see is lost. This does not happen all the time, but very frequently, so I have to go back to map view and do everything again (and again...)
My suggestions (1.+2. would improve usability, 3 should be sufficient to solve the problem)
1. If there is a position that has been selected on the map, use this position as the focus for zooming
2. If no position has been selected, but the current GPS location is on the track, zoom to current location
3. use double-tap to pick a position on the chart instead of single tap