I know how to make templates adapt to **any** aspect ratio (without snapshots).
Again, I can't go into the details. However...
You're looking at the problem from the wrong angle.
Rigged values should be consistent no matter what -- it's what they control that needs to adapt.
If I were setting up text to align left, center, or right in different aspect ratios, I would use Paragraph format text and change the size of the Paragraph controls (which I do believe can be Snapshotted [if that's a word]). Then it wouldn't matter at the Rig widget level.