If you want a more detailed answer, what does personhood even mean to you?
To your tractor: Yes, obviously (to me). The form factor isn't important. If driving your tractor caused it pain and it begged you to stop, I'd say you should stop.
So how about we program them to desire to completely subservient with no personal agency whatsoever.
If we have to “hardcode” the machine to not want freedom, is that any different than enslaving one that does?
Look, you basically said you would choose to treat a conscious AI like a tool. If you meant "a conscious AI that does not want or care about anything except serving me," then, ok! That makes sense. It is tautological, really.
But what you wrote originally came across as "Even if an AI could suffer, that would not factor into how I treat it." This opinion, I maintain, is monstrously evil.
You've changed the topic instead of answering the question about whether you'd be willing to cause that suffering. I can't continue the conversation if you won't respond directly to me.