You wrote:
“There’s not enough information to judge whether it’s a moral or practical issue.”
Incorrect. The law is stated and stated simply enough. You already essentially admitted you understood it to mean blends were wrong to wear. So, if you wear them, are you violating the law (the answer has to be YES) and is that morally permissable (the answer to that logically must be NO). Thus, according to your own logic, to wear blends is morally wrong. Now, do you believe that or do you, according to your own reasoning, deny the law of God?
“I would say that if God said not to do it then there’s a good reason not to do it. That reason may not be evident, but it’s still there.”
So, it is morally allowable for people to wear blends and do you do so?
No, I said God had good reasons for the instructions and we should heed them.
So, if you wear them, are you violating the law (the answer has to be YES) and is that morally permissable (the answer to that logically must be NO).
We're approaching this from different perspective and definitions of "law". Without getting into a study about why laws such as this were added to the covenant, it's logical to conclude that the sacrifice of Christ is sufficient to cover circumstances where we may accidentally wear wool/linen blends.
OTOH clearly there's reasons why God said to do this and we shouldn't do it in a Godly society run by God. But we don't live in these types of societies anymore...or yet.
Lacking information, if you want my opinion I don't wear wool/linen blends. And I don't think God is going to smite somebody for doing so. But if someone wears them with the specific intent of disregarding this prohibition then I think they've got deeper issues with God than what they wearing.