I completely agree with the original idea, profile specific start/end gcodes would be a really good thing.
This isn't a solution to me, because I have 6 different type of 3D printers, and the most of them has a few material/profile specific setting, which must be entered by hand every time.
Just an example, I have motion filament sensor, which is uneffective with TPU material, so I must turn it off before I start a print, or it will fail within a minute after start.