As per title. Does the RR ability stack or is it considered the same “proc” similar to 2x ring dots/RR?
They don’t stack.
If it’s the same skill, doesn’t stack.
it will be op if it does
Even if it did stack, it wouldn’t be op. It would be just an extra -8% Aether and Lightning RR, it doesn’t make much of a difference.
-25% attack and casting speed. X2 = 50%. basically 50% more defense, just theoretically. 
Doesn’t work on things that actually matter because 90%+ slow res on all the major enemies.
Umm, I didn’t think slow resist was effective vs specific attack, move or cast speed…only general slow as in “x% slow Target”. ?
I seem to recall looking at a build stacking attack, cast, move, total speed debuff. And it was effective vs Log, who has 100% slow resist (100% is also typical of a tier 6 boss).
However I did suspect that the seal skill effects other than flat damage would not stack. And possibly not the skill flat, as it may not treat it like SoC or BWC and will simply overwrite the entire effect.
I was hoping someone had tested this to avoid the waste of making a second seal for testing.
Slow Resist affects all slows.
Bosses are immune to such effects.
Hmm. Well that’s weird and now I’m confused. I found that build page link:
If you watch the end of his video, Log is clearly slowed. Grimtools shows Log at 100% slow resist.
Edit: And in a few combats - I thought that there was a noticeable movement effect on Grava (90% slow resist) with stacked CoF and Blizzard Proc. But maybe I’m imagining that with familiarity.
Logh seemed to be moving as quickly (or slowly) as he usually does.
Yup, that’s Log’s regular speed. The speed debuff wasn’t doing anything.
Alright. I guess I was not seeing that one correctly.
As per the seal Aether Corruption skill: it probably doesn’t stack in any way, but I might test it eventually; some of the aura component x 2 do benefit from both and that leaves me curious.
Edit: It is mechanically considered the same skill. Tested and it does not stack in any way, except to extend the duration; spamming either simply increases the duration of the current damage roll. (it doesn’t apply a different value until the spamming and extended duration has expired).