I honestly have no idea what the “official” spec of superboost is. Shimano and Sram officially list the superboost as 56 and 56.5mm (respectively). But they have not updated their documentation for at least two years.
If you read between the lines, super boost got secretly replaced by “sneaky” boost 55mm chainlines. I have been testing the 55mm boost chainline and I can’t tell any difference aside from wider Q factor.
As far as I can tell, only knolly and pivot are still pushing the super boost standard.