Well there’s a few ways to approach the heavy bolt lift problem with Alpha brass. Use a small(er) base sizing die like that, use a reamer with a little extra clearance at the base, or use less powder and keep pressures really low. I personally opted for keeping my standard dies and spec’d a reamer with a little more clearance at the base / datum line. Remember a “small base” sizing die is “small” relative to the chamber it’s being fired in. So if you open up the chamber diameter by .001 (I opened up mine .0015 relative to a normal dasher chamber) then your standard die is effectively a “small base” sizer now.
The real problem is the brass is plastically deforming too much due to low yield strength. Small base dies / larger chambers are only a bandaid fix. Yes, it can work, but the ultimate fix is changing up the mechanical properties of the brass through selecting a totally different material for the cup or improving the hardness and yield strength through mechanical manipulation.
Edit: IMO, this feels a lot like the Norma dasher brass ordeal. Brass dimensions are different, needs it's own reamer and dies, etc. Then it turns out the brass was too soft to push hard anyway. I want to support alpha, they are a great bunch and based in the US, but it's hard to when I can shoot a straight 6BR faster than alpha dasher without heavy bolt lift, and no need for custom chambers, dies, etc.