The Shimano triple had the same 30 tooth inner chainring that they have been putting on bikes for decades. They are still doing it today. Clueless. I also inquired if the 520 could be set up with 24-34 low gears. It took them over an hour to confirm the combination was possible. It was not a good experience.
Shimano isn't "clueless", they are selling most of their triples to road riders, not tourists, so the 30T granny ring is adequate. However, if you find one of the older FC-5703 or FC-4503 triple cranks, they still have a separate 74 mm bolt circle and will take a replacement granny ring down to 24T. The newer Shimano triple cranks (FC -4603 and FC-6703) have the granny ring bolted to extended tabs on the middle chainring and with a 92 mm bcd and are indeed limited to a 30T granny chainring.
As a further possibility, Shimano does make "Trekking" cranks geared 48/36/26 in Hollowtech II format and these have a 64 mm granny ring bolt circle and will take a 22T chainring.