" What counts as 2 good faith attempts, when you have a 2 leg commute", has been a gray area that no one seems to be able to definitively answer. I've heard it from people that DO have 2 leg commutes, that if you make the 1st leg, and are unable to get to base from the intermediate station, that that is good enough. It makes since, why would you strand yourself away from home and base, to get out of work? Having said that, it's not black and white in the contract, and probably up to the cpo reviewing the situation.
Yes, one should always make the best effort to get to work on time. And I'm sure no one is advocating abusing the policy. Commuting a day early, especially when you don't have to, shows a good faith effort, even if you forego the jumpseat. Say you give up a jumpseat commuting a day early, to someone who has to report the day of, because you believe you'll get on the next flight, then don't get on the next one for some reason. I don't think the cpo will have a problem with that. As long as they believe you genuinely tried to get to work, but were unable due to circumstances out of your control. As far as being required to take the JS, I believe that if you're commuting on the day of your trip, then you're somewhat obligated to take it (whilst also meeting JS attire requirments), if it's the last resort, especially if it's on the last attempt. (Unless you are denied, or JS is unavailable. But you may have to explain "why" when clearing the MA). However, JS on your day off should not be a hard requirment, for reasons stated earlier. It's your day off man!