Update on my specific issue.
Well I had the raised ring on the SC pulley milled off flush with the surface that contacts the damper hub. I then carefully cleaned out the threads and reinstalled the 10-24 cap screws. As I was finishing this up I had this sinking feeling as I realized I'd taken this measurement before we started brainstorming ideas. The bolt circle of the cap screws is exactly the same diameter as the hub.
Doh!
So now the pulley fits on nicely with the expected clearance of the damper button heads, but only without the cap screws. I'm a little leery of drilling and tapping the pulley for a stud or set screw without throwing off the balance.
I did some measuring and noted that the area of the clamping surface between the new hub and SC pulley is ~65% larger than the stock damper hub. I'm thinking that with a bit more clamping force as Sean suggests and the added friction from the increased surface area any slippage would be minimized.
I only plan to run this setup in a mild tune, probably 6-7 psi of boost.
Am I thinking about this wrong?