Instead of perpetual UBI, he’s in favor of a larger single lump sum paid out after a period of time post-civil service. The idea being instead of the slow morphine drip of $1k a month for life, you can get, say, $25k-$50k in a lump sum after serving a year or two in the Peace Corps, AmeriCorps etc.
The advantage being service builds a stronger sense of community and gives you more skin in the game. Additionally, a larger single lump sum is more conducive to helping start a business as well as being cheaper long term. It parallels the GI Bill in a lot of aspects.