Which things you can do in GeoSetter which you cannot do in the Map Panel in IMatch 2019?
I'm always interested in potential improvements - unless this something really specific for GPS nerds only
I think this reply will be for 'GPS nerds' only

and I'm quite sure that 'GPS Altitude' has been discussed (and a conclusion has been reached) previously on this Forum, but I'm simply offering this hint below in response to your invitation Mario - in case it might someday be feasible.
I do like the ability in Geosetter to readily obtain an
Altitude value for the current GPS coordinates:
GPS Altitude / {File.MD.XMP::exif\GPSAltitude\GPSAltitude\0}
And frustratingly (for me), I can't get an Altitude value from the IMatch Map Panel, even when I use the Locations or Lookup features.
In some of my pre-defined Locations I've even pre-populated the Altitude value using the Location Editor, and I'm still surprised that that preset Altitude is
not one of the metadata values inserted into my selected files (even with the "Update only empty fields ..." UNticked) when I 'Apply' that Location data to them.
I accept that 'Altitude' is one of the least standardized EXIF parameters, and it's true that the photographer's 'altitude' value returned by Geosetter often needs to be adjusted when (for example) I took the photo while standing on a bridge, or on the ninth floor of a building in a city, but 'Altitude' is still an important detail for me, so Geosetter is my preferred tool at this stage in my workflow.
(In Geosetter, I use the button labelled
Get from Web on the
Location tab in the
Edit Data dialogue. (Accessible via CTRL+E in Geosetter.)
This (Altitude value) is indeed a minor frustration with the otherwise superb Map Panel, and I do recall that we've discussed (and concluded) this topic already in the distant past, otherwise I would raise a Feature Request. Nevertheless, this (GPS Altitude) is the sole reason that I prefer Geosetter for injecting GPS data into my photos