That would be interesting indeed! Maybe there's is a Jah/Cham patterns nowadays (and more of lower ones too... now if only there'd be someone to do a Marvel-style research in this.http://www.diabloii.net/forums/threads/river-of-flame-superchest-drops-project-jah-and-cham-possible-d.655440/
jjscud did lots of testing of super chests, I suggest trawling through his posts.
TL;DR: Stick to LK or take a WW Barb to the council.
Interesting that the jjscud results were pre 1.13. Maybe this is worth reviving?
Really? I can't remember that...but you may be right. I only found his explanation, that visuals were the same for sparkly and special chests in Act V (see link below), but the drops still differ (AFAIK...I even tried some dozen runs in Act V with special chests in the Frigid Highlands).jjscud's research indicated that the drops from chests were properly implemented in LoD, so running super chests for runes should be focused on A1-4.
We started the test runs on the Act IV chests in 1.11b, because 1.12 was released June 12th, 2008 and my PMs with jjscud where we talked about the results are from before May 2008. AFAIK jjscud's later simulations were already done in 1.12. I'm sure it wasn't 1.13.