I've tried this with AWS's HTTP (ALB) and TCP (NLB) reverse proxies/load balancer as a basic proof of concept test and it seemed to work for the 5 minutes or so of clicking around I did. No sort of comprehensive testing.
But a bigger point is that you should strenuously avoid directly exposing Laserfiche Repository Server instances to the public internet, even though a proxy. It's a massive increase in attack surface for the system. Web Client and other Laserfiche web applications have a huge range of built-in cybersecurity protections that are simply not present in the same way in Laserfiche Repository Server.
It's 2025. There are many VPN solutions that support automatic split-tunnel connections to internal resources without users having to do anything. I even have a point about this in my "Securing Self-Hosted Laserfiche Solutions" Empower course: