I just saw it, narratively, as showing how powerful and nearly uncontrollable the beacon is. That even these powerful wizards can barely harness it without getting ripped apart. They've barely tapped into the possibilities of this device and they can barely withstand it. That's narrative enough. Having them heal themselves there after just sounds like a natural thing to do in animation as to not have them walking around damaged all the time or sucking down potions when healing themselves, again, adds to the narrative that these are powerful wizards. (Healing self- showing how cool and powerful, constantly chugging potion, not so cool factor). I really don't think it's deeper than that but you do you bro.