I am trying to upload gpx with HR data and barometric altimeter based altitude data. I cant turn elevation correctiion off and my elevation data gets overwritten. Is it a bug or am I missing something?
There was a bug with the edit-preferences page that was preventing you from changing this setting. It's fixed now, so you should be able to turn correction off and keep your barometric data.
I noticed AP gpx import utility seems to calculate climb only if elevation correction is on. Not a big deal, but I thought it's worth mentioning.