I think when I said it froze, it was before I realised that the camera swap was working after all. It swaps to the camera exactly when it should, and goes back to the 1st Person Camera exactly when it should too.
The problem is only that the camera stays at it’s spawn point and watches the projectile fly off into the distance rather than following it behind as I want it to.
It feels like there’s just that one thing to solve and it’ll be all sorted 
Sorry to frustrate you on this, you’ve been a great help!
Daz