I've had problems with modern monitors shutting themselves off if they don't detect a signal in something like five or ten seconds, which is far too short when I'm trying to debug a PC having boot issues, configure a multi-monitor setup (like a 3-screen virtual pinball cabinet) or even just figure out which HDMI cable is which on the PC end. I don't mind the auto-off feature but the incredibly short time period is unnecessary and the delay time isn't adjustable (at least on the LG monitors I have).

This over-aggressiveness turns a good feature into a problem forcing me to completely disable power saving. Which is sad because the biggest savings of the feature are when a screen is left on for hours when the PC is off or disconnected (which I don't do anyway, as the entire system is on a smart power strip). A monitor should hunt for a valid signal for at least 45 or 60 seconds by default before auto-offing itself.

Another "power saving gone awry" issue is that USB selective suspend can cause wireless mice to stutter after not moving for just a few seconds. I think this is due to lag in the wake-up time. Unfortunately, the interface doesn't have any time adjustment, so I have to just turn selective suspend.

AFAICT my MBP M1 is energy star certified but has no such issue. Might it just be that the Lenovo has a bad implementation?

That sounds like Lenovo just being bad? Certainly they could fix the issue but instead chose the cheaper option.

The cheaper option would have been to not implement the Energy Star feature that dynamically powers the chipset on and off.

Interesting. I had similar things from other machines, and the solution is to keep a silent audio file playing in the background at all times, then there is no latency.