Re: Best solution ...
The thing I notice about people who are so anti-UI is they never seem able to come up with a viable alternative. "We can't have UI as it rewards people for doing nothing"
There's an alternative view: why are you proposing to pay money to people who don't need it? By the time you've clawed it back in tax* you'll end up just where you started give or take a few edge cases who'll be better off under one version than the other. Don't suppose that you'll save on bureaucracy**, that never decreases; you'll probably find at least as many people involved in handing out the UI and probably a few more employed to to the clawing back.
*If you don't claw it back you run into the other problem - finding the magic money tree.
**If, by some miracle, you do you'll have put them out of work - was increasing unemployment an objective?