So, after encountering the question on the officall forums;
Does %dmg (lightning, specifically) on bracers/neck/thundergod's belt/odyns son affect proc damage?
I realised, "I don't actually know".
However, I have both a thunderfury and a Fulminator laying around, so I decided to test those two specific weapons.
I did this by stealing a pair of bracers and a neck with dex from my monk alt, and throwing them onto my wizard - neither had any stats that could increase my proc's damage (int, crit damage, XX-XX damage and the likes) apart from the total 27% lightning damage that they provided. I then took off my current neck+bracers, which meant that when I would equip the dex items, I would basicly gain zero damage apart from my modifiers.
First I tested thunderfury - average crits on it seemed to be about 2.6M without lightning%.
I then equipped lightning% gear, and tried again. To my surprise, the amount of damage staid at about 2.6M avg for the crits. Thing is, 27% damage should have seen me WELL over 3M hits (3.3 to be exact). So conclusion - Thunderfury not affected by lightning%.
I then tested Fulminator, and got the exact same result - my hits/crits were pretty much identical, lightning% gear or not.
Second of, I want to see if anyone out there with the other proc weapons available such as:
Wizardspike (frozen orb).
Shard of Hate.
And whatever I might have forgot, would take 5 minutes out of their time to test their specific weapon, and see if they do or do not scale with the elemental% modifiers. Just to once and for all figure it out.
If there's any "studies" done on this already, feel free to link me - a brief search didn't actually give me any results, but I could have missed it.
EDIT: Great, making 7 AM post = title is borked. Wasn't supposed to be a # sign, was obviously supposed to be % <.<.
I don't have any weapon data to provide but they are also talking about this here.
Seems to mostly be a circle-jerk of "OMG SOH IS SO OP NERF" "NO DONT NERF SOH SHOULD BE OP ITS GREAT". If they are to be believed, Odyns+SoH would be scaling with %dmg, but I'd love to get some actual confirmation/test results here if at all possible :3.
You can even get it from Kadala. Although I've spent about ~17000 shards on 1h weapons and only got ~5 useless ones (2x Arreat's Law, Nailbiter, Sunkeeper, and Nutcracker, IIRC).
@OP: May I ask what's the best way to test this? I'd love to participate, but I have no idea how to reliably find out about this. The range of hits and crits is just far too huge to be able to find this out, in my opinion. If there were items with +1000 minimum damage one could at least reduce the range but the minimum damage affix was removed with RoS, apparently.
I tested as stated in the first post, by taking a dex neck+bracer with no other damage stats on my wizard, giving me 27% extra lightning damage. I removed my usual neck/bracer, and then I hit some mobs and saw the proc numbers (cast one spell, see if it procs, cast another spell, repeat), noted them, and equipped neck/bracer and hit mobs again to see if the numbers were changed significantly. 27% is a big enough number that you should be able to notice a difference at a glance (for instance, thunderfury hitting 2.5m per crit should have been well into the 3m's, but it wasn't). The same can be done with other items, of course.
The difference in the proc damage isn't big enough to warrant needing to count procs and calculate a median of those - it's really quite little it changes, and something as big as +25% is, as said, very noticeable.
Has to be said though, for about ~5 months we were explicitly given several Torment-only lists (even one by Lylirra) and the Shard of Hate was never on it. I wonder if it has always been Torment-only or was just recently added. There's also maaaaaaany people saying they god Lut Socks from Kadala and now they're on the list.
I've spent 30k shards on weapons trying to get a Wand of Woh - if that item appears on that list at some time (which I think it should, but I know for a fact that people have acquired it through Kadala already) I'll have a breakdown...