Even small amounts released constantly would continue to harden his shell, in small enough amounts he will essentially outpace it with regeneration, and maybe improve his mana handling skills
I can create a well to lift myself into the air, and some of the energy feeds straight back into the mana gland, some of it hardens my carapace, some of it helps regenerate the carapace, and to top it all off, it gets slightly condensed for free on the way out.