your 1st variation looks the best option to me.. but I have had a 30/42/52 chainset and didn't really get on with it that well tbh...
but the 28/38/50 with 12-24 cassette just feels odd an I can't help feeling that your bottom gear ratio may not be low enough (28/24...)
I rode with the chainset at 26-38-48 last year with a 12-24 7sp for the most part it was ok, the 28-38-50 is just a variation on a 30-39-50 that is common with most modern triples, the 26x24 is lower than my current set up I could go 26-38-48 with 12-13-14-15-16-17-19-21-23 with virtually the same range as I have now which is 29.22-105.2" and the 12-23 26-38-48 would be 29.73-105.2 but a slightly longer middle and outer but each rear gear would be one gear lower so I would be on the 16th opposed to the 17th
The lowest gear I used today (and according to rwgps the max grade was about 9.8%, though i am a bit sceptical about that) 33.6" or a 30x24 it really doesn't get much steeper than that around here, well not for any length anyway, and all the hills I have done in the last week or so I have never gone down to 30x27 or 28 as it was.
The 38x13-17 would give me better spinning options plus a slightly longer gear for those down hilly bits that dont need you to be on a larger front ring. the draw back of course is the low end.