My partner has a CSP card for many years now and I recently discovered that Chase is generously offering a SUB for Sapphire cards in case you are over 5/24 and other limitations which she is.

Could anyone explain to me how it works though? As I understand step one would be downgrading her CSP to something else like CFU for example, after which she could go ahead and apply for a new CSP with a SUB offer included?

Does anyone know if there is some sort of waiting period in that case? Would she need to confirm it somehow if SUB is available again, or wait for mail in offer? Or it's really just a matter of minutes - downgrading and reapplying right away online for immediate eligibility (she's got excellent score etc)?

I would love to hear from someone who did it before just to make sure what's the correct method is.