While I appreciate your enthusiasm, I don't agree that any form of UBI should have strings attached (and having read a bit about it and the experiments that have already been carried out successfully, I'm pretty certain that it's not supposed to). Once people have their basic needs taken care of, they will be able to focus on self-actualization and producing value, I'm extremely confident that we'll never run out of things to do no matter how powerful AI might become.

I warmly recommend listening to “Why Everyone Is Quitting Their Job To Play Call of Duty”, or reading Jane McGonigal's Reality Is Broken, they're both extremely informative and based on a large body of established research.