I am not familiar with the term "burner profile", but I would assume it is the same as a "burner" cellphone. In other words, a phone you can use to make a call you do not wanted traced back to you and your normal usage phone. I assume a burner profile is a account you would create to use once or maybe a few times, to say something hateful for example to someone while pretending to be their friend in your normal discourse. To be duplicitous. An ALT, would be the same concept, in that you keep two accounts, one is your Alternate eqo, the hateful spiteful troll for instance, the other account would be the good guy image, like me for instance.
I am fairly certain (I have no proof of course). That some members here have had Alt. profiles. I Know that some members that have been banned, have returned under different user names.
There are posters, that are not what they appear to be.