b’h’i
kevod harav,
Is there any problem with eating a burger with fake cheese?
Answer:
I think that today, there is a general awareness of the possibility of soy-cheesh (non-dairy), and if one sees a person eating a “cheeseburger” it would be assumed that the cheese is non-dairy, so that there is no issue of maris ayin.
Other than the possibility of maris ayin when eating the burger in a public place (as above, it would seem that this concern does not apply), there is of course no problem in the food itself.