They are telling you that you have a 'free' option, which means they'll replace the housing at minimum. Apparently they see battery weakness and are suggesting not only that those be replaced, but maybe some cleaning, as you had mentioned earlier that you didn't bother to clean it before sending it in. From what I've read here, folks who send in dirty units are often on the path to less-than-optimal response from service.
This is not accurate. You refused to pay and got something; a working unit back in the mail. S&B does not owe anyone 'new' replacements. They are essentially only obligated to give you a functional unit through the warranty period, assuming no abuse of course.
So, you refused to pay and they 'fixed what they had to'. Sounds like you have a functional vape.
I've also enjoyed great cs from this company, through 3 warranty claims; even ponied up for a battery once, but I'm still on the same warranty ride and loving my Crafty-now-Mighty.
Sorry bout the muzzmod, though at least I can feel less lonely, as I've only really seen one other member (now you also) reporting the glue failure besides me (2x, after lots of high temp use). In my opinion as an experienced cabinet maker, yes the torque is a factor, along with the different rates of expansion/contraction during wild heat swings that the glass, epoxy and 'plastic' that comprise the mod are subject to. Perhaps this is an item that should only be installed/removed when completely cool, this would put less stress on it.
I'll add that I don't feel any health risk from this 'glue failure'; it remains inert, just a little separated from the glass. I'm back to simply attaching a tube to the Mighty mouthpiece. The water piece stays a little cleaner longer...
...AND the dosing caps, while they have nothing to do with the muzzmod topic, seem to boost the experience, so that's a new treat. I'm starting to think there's something to the idea that they allow a little more convection, and less conduction. Not sure how that can be confirmed, but I'm liking the taste and vape quality! The sessions seem to have a more definite ending and don't devolve into those few non-tasty hits.