Salt all sides of the pork shoulder chunks. Heat vegetable oil in a pot over high heat. Brown pork shoulder pieces until surface is seared and crusty, about 3 or 4 minutes per side.
Transfer browned pork to a plate. Add onions to oil and reduce heat to medium and season with a pinch of salt and pepper. Cook and stir about 2 minutes.
Add torn sage leaves; cook until onions soften and begin to brown, stirring frequently. Pour cider into pot; stir to deglaze bottom. Raise heat to high and bring to a boil. Stir in cider vinegar. Reduce heat to low.
Transfer pork shoulder pieces to cider mixture. Cover; simmer gently on low 1 hour. Remove lid and turn pieces over. Cover; simmer on low until meat is fork tender, 1 to 2 more hours. Transfer pork to a bowl with a slotted spoon.
Raise heat to high and bring sauce to a simmer. Whisk in heavy cream. Simmer until liquid is reduced by half and is slightly thickened, 8-10 minutes. Toss in a pinch of cayenne.
Transfer pork back to pot and reduce heat to low. Baste pork with sauce while it heats through and becomes perfectly tender, and the sauce is as thick as you want it, about 15 more minutes.
Remove the thin white skin from the back of each rack of ribs.
Mix all other ingredients (spices, sugar, salt and pepper) in a bowl and use two-thirds of mixture to coat all ribs on both sides. Place on roasting pan and cover in the fridge for 4 to 8 hours. Save the remaining one-third of spice-mixture for later application.
Get grill up to 325 degrees F then place ribs on grill over indirect heat. Grill for about 1.5 hours (back back ribs) or 2 hours (spare ribs or St. Louis-cut ribs). When finished, ribs should have slight bend when lifted and bones should start protruding from ends. Fifteen minutes before cooking time is complete, season ribs with remaining spice-mixture.
Place eggs in a large saucepan and fill with cool water. Slowly bring the water to a boil over medium heat. Once boiling, remove the heat and cover the saucepan for 10 minutes.
Drain water and peel eggs shells from the hard-boiled eggs. Cut each hard-boiled egg in half, carefully scoop out yolks and place in a medium bowl. Set the egg whites on a serving plate, cut side up.
To the bowl with egg yolks, add mayonnaise, 3/4 of the chopped bacon (leaving the remainder for garnish), diced avocado, cilantro, lime juice, cayenne pepper, a pinch of kosher salt, and a few turns of black pepper.
Using a fork, mash and stir the yolks until all ingredients are well-combined. It won't be smooth, but you don't want any big chunks of yolk remaining. Season to taste with additional salt, lime juice, and cayenne pepper.
Transfer yolk mixture to a small zip top bag. Seal the bag, then cut off one of the corners to create a small hole for dispensing yolk mixture. Pipe the yolk mixture into the wells of each egg white.
Sprinkle with reserved chopped bacon and light dusting of cayenne pepper.