Is it possible to get some detail on mob stacking specifics?

• Distances
  • Within x blocks, 3 or more matching mobs will stack
  • Beyond y blocks, mobs will not stack
• Mobs separated by fences will/will not stack
• Leashed mobs will/will not stack
• Named mobs will/will not stack
• List of mobs that will stack
  • On an island
  • In the nether
  • In common spaces (ie: /warp passive)