100~500 is not a lot on ephemeral but it's really not that important an issue.
I thought your assessment of 1% azure kill was a bit too precise was all. hard to tell on 360 or PS2.

most mages with an ascetic's tonic can achieve 100~500 quite easily actually. but again, it's not that important an issue. I would assume not to spend an evening getting exp this way anyway. parties just get used and mages typically leave from boredom or better offers (say yellow procs for seals) anyway.