Looks like random, I can get it in a world with small amount of lights and constructions, but when amount of light and constructions are large it become more noticeable. On previous version same world didn't give any such lag spikes
Not sure what could cause this... If you run into these lag spikes again (especially if it's happening more frequently), could you maybe send us a report? So we can check at least if there is maybe an error occurring in the background 
 
		 
		
		
	 
			
									
		
 But as 	sharkbitefischer mentioned, you can also use the F7 removal tools in creative mode to easily get rid of large amounts of construction elements.
    But as 	sharkbitefischer mentioned, you can also use the F7 removal tools in creative mode to easily get rid of large amounts of construction elements.


 But such an undo-history (where you can see and select the individual undo steps) is on our to-do list
  But such an undo-history (where you can see and select the individual undo steps) is on our to-do list  Or more precisely, the shadow caching. Do you still experience this lag spike if you disable shadows?
   Or more precisely, the shadow caching. Do you still experience this lag spike if you disable shadows?