I found what I was looking for in the second pdf and now I understand why my description was confusing.
Dolby recommends either wide dispersion speakers (over 45 degrees) If you are planning on placing them facing downwards (meaning facing the floor) or angle narrow dispersion speakers towards the listening position. so angling them is allowed in an Atmos setup.
They don't mention a specific angle though, they just say "angle slightly". Should I be aiming for a sweet spot based on the tweeter's dispersion or is the logic between height and front speakers sweetspot placement different. Like the bipolars for example that are not meant to give you an accurate representation of the exact direction of sound behind you, are the height speakers meant to be directional or just give you a similar feeling to bipolars/dipolars?
The reason I am asking that is because if I can calculate the right angle, I can order some custom made speakers, with the drivers placed at the correct angle and simply place them at the right distance on the ceiling. That way I can skip the guesswork.