Connection Timeout Updating or Installing

My HA sits behind a reverse proxy and I am having trouble with updating and pushing configs to my ESP32 devices due to the length of the build process. I have extended the Server Timeout on HAProxy to 20 minutes, but it still times out most of the time. Is there any way to separate the build process, so the image can be built in the background, then deploy the built image to the device separately?
HA is running as a VM on an ~2014 Xeon and has 4 cores assigned and dynamic memory that is currently ~10GB.
The process does appear to pick up roughly where it left off as multiple retries usually gets through the process.

Command line should be able to run detached but I don’t use so cannot verify.