Layers are an important aspect of drawings. The identification, selection, and modification of layers itself as well as contained objects are crucial for the efficient work. https://help.libreoffice.org/Impress/About_Layers This meta bug is also part of the vector drawing capability.
On Hackfest Hamburg, April 2018, we have decided to start a project for improving layer handling and internal structure. For information contact me (rb.henschel@t-online.de) or Armin (Armin.Le.Grand@me.com).