The payment is due at the time of appointment. And the process could ‘slow’ down from that time to the issue of the card itself - which is when one atleast starts the clock as per the proposed new regulations.
If I was not into the process with the first card, I would look for ways to wind this process down and walk away. Even now, I am on the fence if I want to pay for the next renewal (and the one afer that etc even as the ‘moral clause’ of the minister will likely result in more changes to when one can ever get a passport)