If the reader goes to
serif, which is the second choice is because it does not find the
literata one.
I always embed the fonts in, as a matter of precaution, then subset them to gain space, it may one day that I have to port the epub to another reader and I do not want to start reworking 1000 of them
Amasis on T3 is "castrated" as it has not all the characters found eg on T1.