Check all nameplate related CVars and decide for which one ThreatPlates should provide configuration options:

• nameplateMaxDistance (e.g. 30 => 45)
• nameplateOverlapV ( e.g., more like 0.6)
• don't stack nameplates up at screen edge, but move out (remove edge mergel)
  • nameplateLargeBottomInset (e.g., -5)
  • nameplateLargeTopInset (e.g., -5)
  • nameplateOtherTopInset (e.g., -5)
  • nameplateOtherBottomInset (e.g., -5)
• UnitNameFriendlySpecialNPCName=1
• UnitNameHostleNPC=0
• UnitNameInteractiveNPC=1
• UnitNameNPC=0
• Positioning of nameplates at the border of the screen:
  • nameplateOtherTopInset
  • nameplateOtherBottomInset
  • http://us.battle.net/forums/en/wow/topic/20748546958

Already implemented in Blizzard Settings.