I think that a more general version of that overall protocol could lessen the potential harm therapy is causing. I strongly agree that therapists should warn about potential harmful effects and significant chance of failure altogether (with AIT being just one of those) - just like possible side effects have to be listed for any medication. Somehow, with medication/medical procedures in general, it's more of a standard to warn patients about risks and side effects, and more trivial for people that there tend to be some. Whereas with therapy
... it's not so trivial, so I reckon there's even more need for professionals to point out the possible 'side effects', yet they do it less.

The one exception of Ts trying to actively prevent idealisation - I agree with Rive. there, it just doesn't seem possible, and as far as I can see would more likely to just result in T acting like a robot.

I don't know how most people work, but my transferences (the strong ones anyway, that still bug me months afterward) result from a very strong need/drive to have/relive a certain type of relationship. Meaning that my perception might be at least somewhat screwed to begin with, favouring stuff that can be interpreted to fit those moulds.

So, I don't think therapists should be held responsible for bringing about any transference (apart from actually following the ethical guidelines already in place, which isn't always the case), but I strongly agree that once it's there; and it's painful for the client and/or disruptive for the therapy, they should bloody well work on trying to keep it manageable. Like, cut back on behaviour that feeds it, pay attention to own counter-transference, use supervision, and yes, try not to get defensive, but if they do then at least admit that they were, and not double down on it. And yes, maybe sometimes none of that will help, and that's where the client's responsibility comes in, but some damage might indeed be unavoidable even if both parties handling the situation reasonably well.

This is technically true, but kind of similar to saying "why don't you just leave" to someone in an abusive situation. I mean, you go into details later, so I get that's not what you mean, but ... still felt the need to point this out. So long as the client is in the throes of an intense transference, that autonomy and agency is more of a distant goal than something that can be reasonably expected of them, especially if they have to summon it up despite the therapist's 'help'.

Basically, therapists should ideally notice (or at least listen to clients pointing out) when damage is being done, and do appropriate damage control.