It needs to be universal so it doesn't penalize work. If there's any set limit, it'll create pathologies around it like people not taking up a job because it would lead them to loosing money/time.
This sort of "progressive" guaranteed income would satisfy this incentivization-of-work requirement, while still dishing out a fund to people in need.
If you don't reduce total payout based on other income sources, you're describing UBI (or perhaps paying people extra when they earn money, though at first blush that alternative sounds fraud-prone and unstable).