(Does) Occ. Absorbs Magic Damage (stack)?

That'd probably be the most efficient test. You'd just have to make sure each nuke is hitting the 85%~ threshold. Keeping the target alive would probably be faster than waiting out the reraise delay each time though. Might need some support to maintain it.. or.. maybe just have the target be a WHM? Empy legs doing work on the MP costs. Nuke them, they cure. One you've got the nuke value and target HP adjusted, you'd pretty much just alternate spells.

The gearswapping restrictions in PVP make testing there pretty annoying sometimes, though. Can't just walk in and behave normally. Need to lock in a set that does what is needed, or eat an 8~ second stun on each equipment change.

Still, being able to control factors fully this way should be much faster and more reliable than trying to find a mob to cast on you.

EDIT: Actually, if you could reel in some other players/characters... You could spam ga spells on however many ppl you can get. More samples per cast. Although, making sure everyone is taking 85%+ dmg per cast gets slightly more complicated. And they'd all need to have shadow+Archon ring.

What about raetic bangles? Any idea how that interacts with other absorb/annul gear?