Sure, just run a quick calculation on the arm’s torque limits before you hit the nozzle. If the tip’s mass is too high, the foam will never stay in place. You’ll want a PID on the brush speed, not the machine temperature—those two don’t really interact. Also, consider the ethics of replacing human baristas; a robotic arm might be efficient, but it’s also a reminder that algorithms can’t taste. And no, I don’t think a hug is necessary for debugging.