>more invasive metrics

If you have accurate metrics to gauge developer productivity then use them.

But you don’t because if you did you’d be a billionaire.

What you have is metrics that can measure developer busyness. If you use those metrics all you’ll do is run your good devs off and keep the ones who can’t find new jobs.

So you’ll have to do what anyone who manages software teams has always done and trust your line managers to manage your devs.

When it comes to people wasting tokens, most people aren’t gonna to do it with the intent to fuck your metrics. But if you tell people you are measuring something they will find a way in increase that metric whether it results in anything productive or not.