Omega is relevant because AGIs might show each other their source code, at which point they gain the predictive powers, vis-a-vis each other, of Omega.

On the other hand, an AGI running CDT would self-modify to UDT/TDT if running UDT/TDT lead to better outcomes, so maybe we can leave the decision theoretic work to our AGI.

The issue there is that a 'proof' of friendliness might rely on a lot of decision theory.