I have swapped out the 30T grannies on more road triples than I can remember clearly. Since 24T is the minimum possible size with the 74mm BCD of 5 arm road triples, that is what I buy. Last one I got for $9.99 on sale. Grannies are nothing fancy. No ramps, no pins, they can be found dirt cheap on sale. No derailleur made is going to wrap that kind of gear range with a 52/39/24 triple but I haven't found that it matters.