I'm not sure when I started noticing this with respect to the updates, but I suspect it was after the ability to "undoblueprint" was added.
When placing multiple of a blueprint in a row (like fence or road sections), I used to be able to just use the arrow keys to move the blueprint to the next location and RMB again to place right away. Now it appears there is a delay (about 10secs or so) before I can place another copy.
Are others experiencing this? It makes it more difficult to place multiple blueprints in a row quickly.