I have an 8.5” .300 Blackout pistol, and currently an 11.5” 5.56 upper than I need to finish filing my SBR stamp on.
The issue if they ban arm braces is that there likely won’t be any grandfather clause, wasn’t with bump stocks or binary triggers in states that banned them.
Obviously they can them become either rifle lowers or SBR them, but if you’ve got half a dozen short barreled uppers you’re kind of SOL.