Masterpress 1.3.6 is a compatibility release. It resolves an edge case with shared fieldsets not working for MySQL 8 when the fieldset is limited to more than 1 post type or taxonomy or excluding any post types or taxonomies.
MPFT_CheckboxList :: contains( Mixed $value, Boolean $strict = false )
Checks if the checked values in the field UI contain the specificed value. Note that the value is the underlying value of the checkbox, which is not necessarily the same as the label displayed (depending on how it is setup in MasterPress).