In many jurisdictions, at the airports, facial recognition is not applied to travellers under the age of 14 and over the age of 79, I believe. Again, that greatly undermines any efficiency gains you get from adopting these systems, while subjecting everybody else to the intrusiveness of having to give up their biometrics. I think that needs to be taken into account when assessing how effective this is.
It is also a safeguard that has to be in place and taken into account, so that these systems are not applied to those age groups where it's known that there are significant drop-offs in accuracy. For the rest, I think maybe an opt-in is okay, but I think a moratorium is still a good idea, given where things are in terms of the rapidness of the adoption of this technology and the ongoing errors that it produces.