Virtually nobody talks about the AMT credit when discussing ISOs and the AMT trap. Everybody assumes that AMT is this horrible beast, and while it's never a good thing, folks would do very well to have an experienced professional look at their unique situation and perform the calculations because it's often not nearly as bad as suggested.
I have a 7 figure AMT credit that will likely never be eliminated in my lifetime. People in this position hopefully all have competent tax attorneys who understand the credit. The reality is that the credit isn't very meaningful to people like me (and I am pretty typical among people who work at Unicorns).