Elevation Adjustment

[scribbly]

but my concern is that if I did that for the whole track then I'd "lose" what the GPS has recorded. Does that make sense, or is that assumption incorrect??

You could only select the positions which you want to change? And there is always undo/redo :-)

Sorry, not clear enough... I want to adjust all the positions, not just some.

I guess this is not too common, but I thought it was odd that the GPS was out and stayed out? But it did, as the track was a circuit and got back to the same elevation