There has been no precedent that i know of, and i am sure PD Halls of Valhalla wont ban them, if we were going to ban anything it would have been firewall and blade barrier at our conception, as you can bet any of the accomplishments of permadeath guilds included a heavy dose of these. But as you have said there is certainly the factor of fun that needs to be involved. its just when i hear one of our communities guild leader requesting a nerf of something due to being way over-powered and unbalanced, it truly is my recommendation that he/she considers adding it to the ruleset, I believe there is already one guild that has banned eternal wands -> not because of over-powered but because of unlimited resources from these items, I on the other hand wouldnt have the patience to use an eternal wand thru a whole quest and cant even recall ever using the number of charges an eternal wand would have during an entire quest.