It's a plan with multiple points of failure, no graceful fallback, and no contingencies, which seems uncharacteristic.

Looked at from another angle, if even part of AM's download takes, then that gives AM an agent in system who is at least in part influenced by AM's thought processes, which is more than she started with. So it's actually almost a guaranteed win.

And from a third angle it may be an extended loyalty test for Breq - will Tisarwat still be alive when AM and Breq next meet up, and what does that tell AM about how her new agent thinks and reacts.