fatshot Not sure, but aren't Poulter and Perez part of LIV Golf, and therefore ineligible for the Senior tour...
Poulter qualified due to being on the Ryder Cup within the last 5 years.
(He has also paid his fines and eligible for the DP Tour)
Stenson qualified as a first year eligible player who has won a major.
He has also sat out a year, paid his fines and is not part of LIV anymore.
Perez is not part of LIV anymore, paid fines and has already sat out a year.
He's on the PGA Champions Tour now. He is eligible due to the all time money list.