What happens when TETU supply reaches 1 Billion TETU?
Maximum supply is scheduled to be reached approximately in August 2025. With enough time it will no longer be possible to use resources from emissions to incentivize yield management activity on the platform, therefore, Tetu's development focus is to build a self-sustaining yield management ecosystem that provides stable and attractive yields for users. Tetu aims to make the development of automated and decentralized Yield management solutions the main structure of the protocol.
What is the tokenomics?
33% of the total supply is allocated for emissions on Polygon. 67% of emission goes to FundKeeper contract. This part of emission will be distributed on the other Networks. Of the 33% for Polygon, 70% is distributed as yield farming rewards to investors and 30% is distributed to the Governance wallet to further protocol developments.
How to know the circulating supply?
To find the approximate circulating supply, simply subtract the TETU amount in the FundKeeper from the Total Supply.

Do all vaults have 28 days of rewards duration? What happens when you reach 28 days?

The duration of rewards only reflects the current state. The reward refuel happens daily with the autorewarder, the doHardWork calls adds some rewards as well.