That sounds interesting, especially your view on rulings being unchallengeable. Full disclosure im Canadian so our system has differences.
To me, the root cause of that tension really stems from what I view as an inappropriate use of the judicial as law writers. It's politically convenient for elected officials to use the cover of some rulings to allow ambiguity to persist in the law.
I think the ultimate cause of this in the US system is the general consensus (which by my read is not the intention of the law) that your constitution is immutable. Rulings on constitutionality are especially important because your constitution is amended so infrequently.
But with any rulings, I think that they should actually be MORE ephemeral, not less, based on the amount of dissent between judges. If a ruling is 5-4, there is a strong argument that the underlying law is unclear. This type of split I think is better resolved by the demand that legislators update or amend the law to add clarity. Judges, as interpreters of the law, are useful in function as a type of "quality check". A 5-4 ruling, I would argue, amounts to the judicial writing law in the absence of clarity.
A 9-0 ruling? Law is fine. 8-1, probably still pretty good.
Even on a 9-0, there is nothing STOPPING the legislative branch from re-writing law. It is thiers to write and rewrite.
I just think tight splits should trigger some mechanism which demands a law-based resolution to clear up the underlying ambiguity within a specified time frame.
I get why legislators were happy to avoid touching law about things like abortion and let SC rulings be thier cover... they're elected. It is convenient and safe. But they're not really doing thier jobs.
Anyhow, that's my 0.02