per John Fjeldsted @ Agilent and the crew @ MOBILion, it would be good to have a view of ion intensity vs ion mobility, as on page 10 of the attached document

From zoom discussion 3/4/2021, we're planning on adding the ion mobility spectrum view to the current heat map view (on the left, summing horizontally).

John F and the MobilIon guys would like that to sum only the currently visible range - that is, it should be zoom sensitive.

I don't think that makes much sense to sum only the zoomed range at the time you click the button. That is not how the spectrum button works. I think we need to leave that feature until we do the 3-panel view, and even then it probably needs to be something you can turn on and off.