Thanks for this awesome peace of research! I'm really looking forward to further developments in the field :)

I have two small questions regarding the paper:

1. When comparing to Normalizing Flows (planar flows), in Section 4.1, how were these fitted in the Maximum Likelihood Training section? If I understand it correctly NF's don't have a closed form inverse, s.t. ML training should not be possible.

2. Do you encounter any issues regarding stability during training? Other Flow based approaches such as Glow use certain tricks to ensure that the Flow initial reduces to an identity transform, to increase stability and ensure reliable convergence.