Thanks Roger, you really explain it well. Learnt so much from you!
I ended up going for the nodal ninja 4 with advanced rotator head. It's a beautiful piece of machinery and finding the PPP is a doddle, the connections and arms are so well built there is virtually no movement between shots and while adjusting the camera's position. This is a fantastic reference, thanks again! I will be posting some equirectangular panos in the next couple of days still sussing out nadir shots though 😆