I know that de Grey has a rough outline to reach his "Methuselahrity", but does anyone know of a reference to other milestones needed to reach the singularity's

I know that de Grey has a rough outline to reach his "Methuselahrity", but does anyone know of a reference to other milestones needed to reach the singularity's state of radical abundance. The notes indicate that they discussed the idea of milestones to the singularity, but I was wondering if anyone has sat down and really thought it through on how to get there. Thanks!