You're thinking of this back to front. You're saying "I'd rather do the easy, invasive thing first; based on that, I'll decide whether I want to try and coach t

You're thinking of this back to front. You're saying "I'd rather do the easy, invasive thing first; based on that, I'll decide whether I want to try and coach them". No. Talk to them, say "Hey, it feels like you aren't performing as highly as I'd expect. Anything up?" and make it clear -you're paying attention to them-. You've now spent time you -should- already be spending (on a 1-on-1), and actually did something to try and solve the problem, rather than to try and make it "easy" to just let them go. If their performance starts to improve now that you're engaging them, great, no privacy encroachment (and if they -were- only putting 2 hours in, and now are putting in more, even better! You avoided the pain of termination and replacement). If their performance doesn't improve, also great; now you can let them go -knowing you did everything you could-. Why the hell would you want a half-assed outcome that, at best, will still require the same effort from you, and at worst will save you no time (again, you should already be having regular 1-on-1s), and leave you wondering if there was more you could have done, and in either case cause a morale hit to your team who now knows you're willing to electronically track them?