[findingpeace]

Thanks for your help, Max! Unfortunately we needed several more options than post count in order to allow PMs.

This hook in pmdata_start did the trick:

if (is_member_of($registry->userinfo, 5))
{
    $this->overridequota = true;
}

Along with editing the template memberaction_dropdown:

Changed

<vb:if condition="$show['pmlink']">

To

<vb:if condition="$show['pmlink'] OR is_member_of($bbuserinfo, 5)">