I haven't made up my mind about UBI, and I do think that it would be valuable to society for all persons to have room to experiment and innovate around ideas (effectively, enable society wide R&D), but I think it's an open question as to whether it is worth the costs.
I already struggle to hire anybody help with fixing the many problems with my house, and it's very inefficient for me to need to learn to become an expert in so many different fields. I quite enjoy it, and there are positive externalities, but having specialists (or just "willing hands") in areas that there is demand for is also quite important to a functioning society.