I don’t think the word “consent” or “agreement” needs to be included at all though. This is just training. Some things are easy to train with R+, others with R-, and while most of us don’t use P+/- on a regular basis we do use it sometimes and it can be effective.
Consent isn’t necessary to learn, but good trainers can see when their subject doesn’t understand and modifies the training method and/or the delivery
It would be possible to teach a horse using punishment on a regular basis but we would all agree that it’s not humane, and more importantly, it’s not necessary. But “consent” is a silly term to add in the mix. The subject can be expected to learn and follow commands whether they consent or not.