FW 5.40 Elevation Plot numbers don't match Basecamp?s

Different sites / services use different algorithms to calculate ascent (think: smoothing). Although I'd expect to see same algo in garmin products I got used to the fact thats hardly a case.
For example trail de trail is a service commonly used to plan ultra races and often serves as a official track source (at least for runs that I do). What happens each and every time is that I end up with more ascent measured by watch or shown in Sporttrack than what was officialy stated. A recent example: official (trace de trail) 4200m of ascent for a race ended up with 5000m (over a 100k course) of ascent according to both Fenix and sporttrack elevation profile.

ok but let's say that 2,285 vs 1,144, the double!!!!, is away to far from being any reasonable ... mainly within Garmin's own products...