eijo wrote:You've never said what you mean by "legitimate", and a better answer would hinge on that.
Meaning a sadhana associated with Mahavairocana requires the Mahavairocana empowerment, so if you have the empowerment, then you should be able to do the sadhana, even without a teacher (the text itself, as I have seen, may not say you need a teacher).
Basically I'm saying you fulfil the requirements as a text states (not external expectations), rendering the practice legitimate. I looked at one sadhana that simply states you need the empowerment.
In any case, it all seems quite subjective and up in the air. At your own risk, so they say.