Plot hole: Luke deliberately says he does not want to be found and came to Ach-To to die in The Last Jedi, but The Force Awakens is all about finding a map to Luke Skywalker. Why would Luke leave a map when he never wanted to be found?
Plot hole: By having Admiral Holdo perform her infamous hyperspace ramming stunt, Rian Johnson created a continuity problem with the rest of the Star Wars universe. Since this maneuver was successful, every space battle before and since should only include a droid piloting spacecraft ramming enemy bases through hyperspace. This tactic would have been more cost effective and less risky than full on space battles seen in previous films. This tactic would no doubt have been tried in a universe filled with space battles often with disposable troops on both sides, such as in the Clone Wars. The Death Star did not need a successful trench run to be destroyed, just an X-wing with a droid ramming it at hyperspeed.