I like the approach. I think however you have to be a bit coy upfront but you simply don’t ever admit about being coy. Where I have been burned is obviously letting the cat out of the bag related to any strategic decisions made in the dating process.
If you boil it down to forcing action over verbiage, which means creating situations which require a committed response on her side, you can always have the feedback you need to determine her intentions.
Then from there, as you said, reward her with your time and energy, reduce or remove the same if unwarranted. I have tried before to use logic and I will tell you speaking for myself, the only two things that ever worked are what I said above, either giving my time or taking it away, it’s the only language they understand.
Put a girl in the penalty box so to speak (go no contact) for 48 hours that’s really into you and you’ll watch her start moving mountains to make it right.