Reload makes new workers. Workers are expensive. Reload can happen very frequently.
In case of proxying websockets, they can be in every worker. Worker can not be shutdown because websocket connections are alive.
After few reloads there are many workers and OOM killer comes closer. So we need to kill workers by ourself. It cause websockets reconnection. That is bad for clients.

It would be great to have opportunity to transmit/assign websocket connection to a specific worker/number of workers. So reload can shutdown rest of workers and resources will be reused.