I may have a solution to the 58% thing. Not sure.
Like others, had my buds for a couple of months. Love them. Then the right one was became stricken with the 58% illness, and nothing I could do would get it to charge past that (all firmware updates, lots of resets, etc.). I gave up after about 3 weeks. Bose was wonderful about it, and shipped me a new set right away.
But while waiting for the new set to arrive, I did something that seemed to fix them - both started charging to 100% again (for several days)! But then the replacement ones from Bose showed up and so I sent the original ones back as Bose had requested. So I wasn't able to do more testing.
Here is what I did. Perhaps someone else can try this ...
(1) Do the usual (put them in the case and let them charge for several hours).
(2) Open the case, but do NOT remove the buds. The white lights on both sides should be on full indicating both buds are fully charged (but of course, we all know one of them isn't, even though both lights are on).
(3) WITHOUT removing the buds and with the CASE STILL OPEN, do the paperclip reset thing by sticking a paperclip into the hole on the back of the case. Careful not to dislodge the buds while doing so. You can tell the reset actually happened, because all the white lights on the case will momentary go out and then come back on again (because you left the case open, you will see the lights).
(4) Both white charging lights will start flashing again, indicating the buds are charging. Shut the case and leave them alone to charge for another hour or so. When I took mine out after that, the right one had charged up to 75%. I used them that night, did normal charging on the following days (just put them in the case and left them each day) and both charged properly to 100% again every day after that.
Maybe it was just luck. Or maybe they are haunted. I don't know. Someone else should try my sequence though, in case it works. I don't think the battery is actually bad. This has the feel of a software/firmware "glitch" where things get into some funny state and the case thinks they are fully charged when they aren't and stops charging them. Good luck! If this works (or doesn't work) for you, please report back here.