Elgato’s core applications (Stream Deck, Camera Hub, Wavelink) do honor:

Variable name: HTTPS_PROXY | Variable value: http://yourproxy:port Troubleshooting "No Connection" on Stream Deck

You set HTTP_PROXY , configure Windows/macOS system proxy, or enforce a PAC file — yet Elgato’s services connect directly to AWS endpoints as if no proxy exists.

The Stream Deck store often fails to load if the proxy requires authentication.

Without the proxy inspecting traffic, there is an added theoretical risk if the endpoint is compromised; however, Elgato likely uses TLS/SSL, so the traffic remains encrypted, just uninspected.