As "Oginme" says "Boil Vol Basis", and the other settings described as "basis", is only a place holder. It could be used for troubleshooting a profile before it is in use.
I came across these "basis" settings when noticing there wasn't something quite right about the profile's predictions. The predictions were missing the "deadspaces". Of course they were, the mash profile knows nothing about the equipment profiles! Until the profiles are combined in a recipe that is, then it all makes sense.