Have more sense than to become further acquainted with (4,6)
I believe the answer is:
know better
'to become further acquainted with' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'have more sense' is the wordplay.
'have' becomes 'know' (synonyms).
'more sense' becomes 'better' (I can't explain this - if you can you should believe this answer much more).
'know'+'better'='KNOW BETTER'
'than' is the link.
Can you help me to learn more?
(Another definition for know better that I've seen is " Be wiser".)