I have a DI engine (Volkswagen 2.0 TSI), the carbon build-up is very annoying / expensive. I think they still have not fixed it, but not entirely sure:
Oh yeah, I used to have a used BMW with an N54 engine with the same issue. I ended up buying a media blaster, crushed walnut shells and cleaned up the ports preemptively.
CRC intake cleaner seems to work the OK for a homegamer solution. Make sure to follow directions, as they are not obvious. Best used every 20k or so on GDI engines.