General global altitude field offset about flightplot HOT 1 OPEN

That would be good if we have log format with standard fields, but we have no one, each autopilot has own field names with different names and meanings and to do it correct way need to handle all cases (APM, PX4, PX5, etc...). So not sure that it's good idea to add new hack. Offset field is always available, moreover baro and GPS have large offset so to compare them user must adjust offset manually. Maybe it's better to:

• Provide some method in GUI for easy drag-n-drop moving of lines on the chart? That would be more useful maybe.
• For ANY line add checkbox "adjust vertical offset so line starts from 0 at start of log" and/or "adjust vertical offset so line starts from 0 at start of view", this would be useful not only for altitude but also for other cases, like integral of acceleration.
• Other ideas?

from flightplot.