Trust me you wouldn't want to go backwards and create one hole in a vacuum essentially making you replant and recreate any adjacent holes over and over like you had to in years gone by. Those days are long gone and good riddance.
What we have in it's place is a system using LOD which means objects in the distance are rendered at much lower detail.
Can I ask you...does the game render "behind you"?
Could "not doing that" perhaps help with performance overall?
(maybe a stupid question...but hey..why not learn, right? - haha!_)