Currently we have a problem with $variables and $maps and overriding those at a Pattern-Lab level. Especially if one of those values is dirived by a mixin, using an imported $variable like $fontSizeBase, as the declaration or calculation is based on the value of the dependent variable ($fontSizeBase) at the time it is @import'ed to the mixin, not when the SCSS is compiled.
SASS variables are not references.
//# Defined in sass-library
$fontSizeRoot: 16px;