Is causal decision theory plus self-modification enough?
No.
It is true that CDT with self modification is unstable. All CDT agents will instantly modify themselves to be agents that behave as if they are UDT agents with respect to information about external decisions made after the time of self modification but will interact with all external decisions made before the time of self modification based on CDTlike reasoning.
It isn’t possible for a CDT agent to escape this constraint through any effort of self modification because it is fundamentally against a CDT agent’s nature to try to do so.
No.
It is true that CDT with self modification is unstable. All CDT agents will instantly modify themselves to be agents that behave as if they are UDT agents with respect to information about external decisions made after the time of self modification but will interact with all external decisions made before the time of self modification based on CDTlike reasoning.
It isn’t possible for a CDT agent to escape this constraint through any effort of self modification because it is fundamentally against a CDT agent’s nature to try to do so.