NOOP interval/keepalive feature

Is your feature request related to a problem? Please describe.
We experience on many machines, socket.io won't detect all websocket/tcp/network disconnects (like terminating vpn process, ripping out network cable, ...), until the ping-pong messaging occurs. But if we try to use the websocket (by sending something)
after the network loss/change, the disconnect is detected immediately by socket.io.

Our solution to this, to keep the detection time short, and avoid having too short ping-pong timing (which might cause issues if you have slow startup/wake, maybe lots of events?, high RTT?), has been to send a engine.io noop message every 2s. With that we detect network loss within 2s from the client side.

As a bonus it seems to keep some small portion of websockets alive, maybe because of increased traffic, that used to break somewhere approx every 5m. The default ping interval didn't stop this, but sending this noop every 2s seems to.

Describe the solution you'd like
It would be nice to have this as a feature, noopInterval or something like it, just sending noop or something else periodically when the connection is supposed to be open. Or some other way to solve the problem.

Describe alternatives you've considered
pingInterval+timeout, but we're afraid of setting those too low.

Additional context

Start by reviewing the engine.io ping/pong and noop behavior described in the issue, including how pingInterval and timeout currently detect disconnects. Define how a configurable periodic noop would interact with open connections, then verify that it detects network loss promptly without introducing overly aggressive ping-pong timing.