I think it's that they spawn closer to the player and to the edges of your base than they used to for sure....and also they seem to spawn in a larger radius as well.

Before the update I could ignore all but the worst raids since my perimeter is far enough out that I get very few spawns at all, even at night. Now I'm having to pay much closer attention to damage being done to my exterior wall and gatehouses than I used to.

I almost wonder if they have changed the spawn behavior to spawning around workbenches instead of just around the player. So now even if you have a large workbench net around your base, if the area is close enough to be loaded, then spawns will treat each workbench as a viable spawning trigger. That could also explain the significant uptick in CPU usage since the update.