Consider that the persons who shot up the road signs probably will not be flagged by a background check because they have not been convicted, they are unconvicted criminals.
How can the SCOTUS be in violation of the Constitution? The Constitution makes SCOTUS the last word on Constitutionality. If a SCOTUS with a Conservative majority rules that some gun bans are OK, that is what it is and your remedy is Congress or the States.
You really imagine they will overturn NFA 1934 or GCA 68. We can’t even get Congress to fix the law regarding suppressors.
More and more I have been moving toward supporting background checks, more extensive and intrusive background checks and even competence test and registration of gun owners. It is too easy for the ignorant and incompetent to get guns. Yes, it will not stop criminals but it will keep guns out of some unqualified hands.