Q: is anyone seriously discussing Soft Secession?
A. Yes. But also It's not something that has to be discussed to advance, in fact it's already been in been practice on and off throughout American history.
Soft Secession is just states deciding to ignore federal decisions. This has been overwhelmingly employed in terrible regressive ways. That doesn't have to be the case.
Republicans have used this tactic in a particularly effective manner during the Biden admin with Sanctuary Laws for guns, doing everything they could to find loopholes around Roe V Wade, and even actively going against federal policy like Texas did with immigration under Biden.
Another example of Soft Secession in action is states legalizing and decriminalizing cannabis which created pressure and effective nullification of ridiculous federal policy.
They don't need to be talking about it to be doing it.
Free school lunches? Soft Secession.
State level replacements for SSI and Medicaid? Soft Secession.
State's collaborating to create a Blue State Education Alliance that uses research backed policy to inform decisions? Soft Secession.
Soft Secession is advanced states rights. Whether it's used for good or evil is up to We The People.