Tim I think we're referring to the same thing: the experimental "extrema markers" features in V6P only, never officially released. My desire to do more with these (such as tracking/logic integration into concepts like map-view-locking, but also possibly inter-frame path display, etc) is one of many examples where the engine was too limiting in first-gen and created additional value prospect in starting over.
The extrema labels feature I am planning to fully build is very powerful because it will work on any raster layers - even mapping data. While it won't make sense for color data (such as the RGB orthoimagery background imagery), it will be extremely useful for static elevation data. For the base mapping engine, I want automatic max per-view elevation markers on the background map just like the min/max labels get automatically placed on timeseries dynamic raster datasets.
I envision controls for possibly allowing multiple extrema labels as divided by zone on screen, enforcing a minimum distance. The problem is, some types of data are very noisy, yet for others it works very well, like pressure.
I envision to have a whole "HUD" system that performs real-time tactical analytics on arbitrary raster data, extending this concept. Let me know of any other tricks you can think of for real-time informational statistics, extrapolations, or visual markers on arbitrary raster datasets.
Another one is dynamic color palettes - just like the sliding "hypsometric tinting" feature in the first-gen 2016 background engine on the terrain colorization, except extensible to all raster parameters. This is where you specify a 0..1 color palette and the value are mapped to the min/max of whatever values happen to be currently on the screen.