Ok I'm thinking this in regards to Heralds:
Option 1: Everyone who scales to Thor scales to Yggdrasil. Heralds end up at probably High 1-B. This would be everyone currently 3-C or Low 1-C being upgraded to High 1-B.
Option 2: Same as above but we treat Yggdrasil as 2-A, and everyone becomes 2-A.
Option 3: High Heralds scale to Thor's Yggdrasil feat and will be High 1-B (Peak Thor, peak Hercules, peak Hulk, Thanos, Sentry, Kurse, Mangog, 2nd key Silver Surfer, maybe Ultron). Normal Heralds (Everyone currently Low 1-C or 3-C) scale to 2-A based on Eric Masterson's feat and hopefully some supplemental feats.
Option 4: Same as above, but if there are no other feats around 2-A, we might have to drop it. In this case, something in Tier 3 or even as low as Tier 4.
My thoughts on the scaling are that nobody should scale to feats done by characters like Thor, Hulk, Hercules, etc., but they should be able to scale to their normal states. So if we have statements of a character being on Thor's level, that would be treated as them scaling to Herald Tier. Characters who are explicitly and consistently more powerful than someone like Thor should either scale to his soon-to-be High 1-B Yggdrasil feats, or get a "possibly." I think Ultron falls into this category as to my knowledge, Thor has never so much as scratched him. Characters like Sentry and Thanos should be a flat High 1-B as not only are they shown to be more powerful than Thor, they also have feats against Skyfather Tier characters.
My thoughts on Thor's scaling have changed. For one, only one of his Yggdrasil feats is him in a "Beyond peak" state, the Worldengine feat. If even literal baby Thor scales to Yggdrasil, I don't think we have a reason to think he only scales to Yggdrasil at his peak. I also think he operates at "normal" Herald level 99% of the time. In Blood and Thunder, when he was shown to be vastly more powerful than Silver Surfer, Beta Ray Bill, and Adam Warlock even before getting the Power Gem amp, Sif thought his strength was amped 10x by Warrior's Madness. It wasn't, this is just how strong bloodlusted Thor is. This is important because it shows peak Thor is vastly above Herald Tier, but also that even Sif, a fellow god, had never seen him this strong before, so she judges Thor's strength to be comparable to those three.
I don't want to do a CRT yet, but I want to hear your thoughts on my thoughts so far.