I honestly don't see how this could work. Sorry, not trying to be negative but why would adafruit (or any place else) do this? Especially for free. Yes, I can see how it might increase customer loyalty but I can think of a lot of better ideas for customer loyalty. Like responding on their own forums to questions about the products (good job adafuit!, unlike sparky outfits). You pointed out the various customer service issues. And, the question any company should ask when adding a new service (or product or activity) is "does this support our core mission". And, frankly, I don't see how this idea does though I don't speak for AF.
For people and suppliers in the US, USPS first class shipping on light packages (less than a pound, I believe) isn't very expensive and takes a couple of days. I think every supplier I use has that. My last mouser shipment was $4-ish and maybe weighed 8 oz. So, they would be catering to people who are to save few bucks. I dunno, not really a good use of scarce resources.