Thought I read that it was, but my 20 Rogue/5 Shadowdancer doesn't seem to add it in.
My SA is listed at 23d6
10d6 -Rogue 20
3d6 - Assassin 3
4d6 - Capstone
5d6 - 5 Shadowdancer
= 22d6
So it looks like I'm only getting 1d6 from the ISA.
Or I'm completely oblivious and missing something obvious.
Answers either way (not working/missing something obvious) welcome.