No question about the gear spacing being a potential issue for certain riders in certain conditions. I got the impression based upon what the OP said that he tends to be a casual rider with a fun type ride in mind. Being a casual rider, I haven't found the gear spacing of my big cassette to be an issue at all.

I'm running 12-30 with a short cage 5700. Works fine.

I think he meant what Shimano specs rather than what is possible, though it's only correct for 11 speed. Prior to 11 speed there was no difference in max cog for SS or GS. In actual practice, I've also used the 30t on 6600, 6700, 6700A, 7800 and 7900. On one bike the 7900 works but the 7800 does not. Just have to try.

I miss riding mountains near the coast. Spent 7 years at Moffett & riding the Santa Cruz mountains. I love it out there, what I don't love are the housing prices. House I lived in in Cupertino (DeAnza & Stevens Creek) is now valued at $2.6M, was $100K when I lived in it.