the PhotonTransformView component worked fine in our internal tests, 
but we receive more and more (negative) feedback about it, so that we have 
started to look for another (and better) solution. Unfortunately 
I can't give you any ETA about the new version. In the meantime you have 
  different possibilities:

1) Simply wait for the new version.
2) Update the PhotonTransformView component from PUN Classic to make it compatible with PUN 2.
3) Try using the PhotonRigidbodyView component. I know you don't use it for movement, but the Rigidbody component relies on the Transform component and its data as far as I know. Means that you can try to use the PhotonRigidbodyView component although you don't use the Rigidbody itself (at least not for movement). When using it, make sure to not use its Synchronization Options (velocity and angularVelocity).
4) As you propsed: going back to PUN Classic, but I think this is not necessary.