I've been researching this for an upcoming holiday, consequently I am now inundated with adverts from testing clinics. This one keeps appearing, note that I have no experience of them as yet.
https://www.haleclinic.com/pcr-test-for-travel who promise a quick turn around and claim that only Cyprus ,Barbados and Hong Kong require a time stamp on the test.
Their information may not be up to date, given that Seychelles has effectively been closed until now, but with the evening flight time it would make a big difference if 48 hours does just mean 2 days with no date stamp required.