I lean towards a harsher interpretation. Preservers defile, no its, ands, or buts. They RIP from the land no differently than defilers.
The difference comes afterwards.
Preservers attempt to restore. At a greater cost than what they took.
My logic behind this is that Athas is already damaged, scarred, and hemorrhaging. ANY use of magic savagely tears open the wounds even wider. You’ll have to pay through the nose to even attempt to preserve what you just selfishly took from a wounded and dying planet. Let alone succeed.
Magic will never be able to heal Athas. At best it can pause the downward slide briefly.
As such, the Rite of Blood requires willing sacrifice in the form of damage greater than what was dealt, or greater than the end result or effect, if not damage. Of course, one can opt to give up their life in order to accomplish some real healing… but oddly that’s not a real popular option. Can’t imagine why, everyone used to have to make a stable of characters before even playing.
Anyway, while that’s how I run it, that’s just my unsolicited opinion. I don’t have any references to quote that add to the original request. Apologies.