for the injectors, i would just take them to the machine shop just to be safe... you can dremel that 2mm but you have to make sure its fully round and wont leak because of a hairline slit because of where you dremeled
i asked the tuner he said it was fine just dont bore it out too much where its easy to drop the injector in. so i have a drum sander on the dremel thats what i did it with and it used different grits to make sure it was shiny again.