But the https://www.gw2tp.com/item/43773-quartz-crystal does not appear to have exploded, since ArenaNet was quick enough to fix it. Or maybe it’s true and the exploit did not even consume the stacks and you could get unlimited amounts of Charged Crystals == Provisioner Tokens for free while it lasted.
I can craft a bit and sell it
Probably not, since ArenaNet crashed the market for (crafted) exotic gear with the addition of a new https://wiki.guildwars2.com/wiki/TEID-07_Unified_Vendor_System who sells stat selectable exotics for very little coin and honor. If I were mean, I could say they did this to make people buy PoF and HoT so they can also pick stat combinations from these expansions. Anyway, crafting is now officially dead.