True. Ego death can probably occur with any psychedelic compound. With most substances however it is a matter of dosage. Eating 8 grams of Cubensis might get you there. The dosages that e.g. the MAPS program works with will not (yes people have different responses, but that is why you start low and they have professionals attending).

Going for a true Bufo experience automatically puts you in the realm of possible ego death. I have never heard of anyone trying to micro dose it. There are so many other substances that are easier to low dose that are more readily available too.