Thanks for the detailed explanation. It's clear what you are trying to explain.
I just have one question. Does making the extruder think that it is in a different feed position and giving it a new value, also affect the filament quantity that is shown on the 3D printer? Say, I jump from E100 to E200, does the printer think, the 100mm of filament skipped as already used and reduce that from the quantity left?
Because it's a common printer shared by multiple people at office, I don't want to confuse them with these kind of work.