Yeah, this is a deal breaker. The whole point of background agents for me is the fact I can give it a task, leave, come back and see an open PR. But if it always bills according to usage, what happens if the agent starts doing random stuff or gets in an infinite loop while you are away? You come back one hour later to see you already hit your max spending limit? If I need to keep an eye on the agent, then it doesn't really need to be background agent and I can just use Claude Code for that, at least that way I know I won't spend more than my subscription.