Use static ips for AWS Application Load Balancers

Our requirement is to

1. Assign static IPs to an ALB, because many of our customers have whitelisted it in their firewalls.
2. The X-Forwarded-For HTTP header should contain the clients IP address, because we have a https://www.whatismyip.com/ like service running which thousands of our IOT devices already use.

Tried following solution but it does not do #2, we see the internal NLB ip instead of the client IP in the X-FF https://aws.amazon.com/blogs/networking-and-content-delivery/using-static-ip-addresses-for-application-load-balancers/

Is there any load balancer out there that can do #1 and #2 or can AWS make this happen on request? Any help/pointers appreciated, thanks!