I think it’s just a language barrier. You do not have to delete it every time, in fact you are actually inserting it every time.
Shown on this page under slicer edits, it is shown, remove the g28 command. http://www.vicious1.com/import-extruder/
Attached is a pic from simplify3D, just deleted that command and it will not add it to your slices.
There is absolutely no reason to touch the firmware, you gain nothing.