How do you handle healing spells in Donjon?  It looks like you can keep casting healing spells between encounters until everyone is fully healed.  Moreover, the recommended method for resolving magical healing attempts (setting the difficulty equal to the damage suffered by the target) looks like it would lead to the counter-intuitive result of encouraging you to heal the least injured characters first.

What house rules for healing magic have people tried, and what were the results?

When casting a healing spell, the mage gets additional dice equal to the remaining Flesh Wounds the target has. The casting roll is considered a Hard task. The Donjon level is the same, as it was, when the wounds were received.