@dantraMSFT
Some things will be rather difficult to do, providing a partial solution should be doable, but something like the following might not be possible via inspection (given the following m.psm1 file)

$var1 = 1
$var2 = "a"
$vars = "var1","var2"
Export-ModuleMember -Variable $vars

It would be quite difficult to catch that via the ast since it means getting a runtime value, would a partial solution be better than no solution?

+1 on the request. A partial solution -- by which I assume you mean a simple parse to locate an export that matches an assigned but otherwise unused variable -- would work for me.