Can I connect to the accelerator using HTTP_PROXY?

Our corporate license server and our corporate accelerator deployment are in a different network and we need to go over the proxy to hit them. I've set HTTP_PROXY and seen that the license server is using it, but I'm unable to connect to the accelerator. Does the connection from the build to the accelerator respect HTTP_PROXY? I saw that we added HTTP_PROXY support in https://forum.unity.com/threads/how-to-set-proxy-server-for-auto-update.910376/, but that seems like it's code IN the accelerator - i need to proxy the connection TO the accelerator.