Using NLB as a listener for HTTPS

Yes it would be possible to terminate HTTPS (TLS) traffic with NLB, by using a TLS listener as documented here.

Generally speaking, we could think about if ALB's layer 7 features such as WAF or Advanced Request Routing would be of help, otherwise LCU cost of NLB is slightly cheaper than ALB from the connections perspective. Refer to the pricing page for more details.