My previous CSR bonus posted on a statement with a closing date of 3/3/2017. PCed the CSR in late 2020 and do not currently hold any other Sapphire cards. I tried applying in-branch for the CSP today and the system wouldn't even let them do it (which they then tried to claim was because it has to be 48 months from account closure, not last bonus ) so maybe it's not an exact 48 months? And here I thought I was being safe waiting until April guess I'll try again next month.