I know it’s not an answer (I’ve been trying to find blue dot locally for some time as it’s my principal duck load powder) but for target/proficiency use in .40 SW, you can use a huge variety of powders to roughly equivalent velocities… been there, done that for my USPSA limited gun.
It seems that all the Alliant powders have been hard to find since 2020.
I was going to suggest switching to one of the varieties of Hogdon Clays, but they're just as unavailable.
Checking my burn rate chart VV N350 looks like it's a good substitute, and it's available at Natchess for $160 for 4lbs, with free Hazmat today only. code FH240105