I am working with it and hadn't experienced any issues until I tried placing a pier floor tile (wood floor with the 9 stilts) in the river in Sanctuary. I could not place it where I usually am able to (I like making a large generator shed next to the water purifiers keeps the noise away). I checked on somethings as I am also using the undamaged sanctuary bridge which says not to use bUseCombinedObjects=0 if using Spring Cleaning. So I checked my ini and it was in there, I don't recall what I put that in for to begin with to be honest it's been awhile since I played FO4. I removed it and once I loaded the save if I moved closer to the settlement bounds I was immediately kicked out of build mode like I had crossed the boundary and ran out of time. Still didn't fix the issue with placement either so I added the bUseCombinedObjects=0 back in, boundaries were normal again. Do you happen to have bUseCombinedObjects=0 in your ini? EDIT - I did some more testing with combinedobjects removed and found that if I zoned into the basement bunker in sanctuary and went back out it adjusted the issue so most likely not what you encountered. EDIT EDIT - After posting that edit and loading the game back up it repeated the build mode boot, if I didn't move np but start moving and bam no build for you! Re-applied the bUseCombinedObjects=0 to stabilize build mode again. The issue you are having is that you are crossing cell boundaries, this is because the combined object rendering is acting up because things it expects to be there no longer are, if you wish to use combined objects, you need a esp mod that first removes scrappables across the world from the list of valid objects to combine. Unfortunately, this is somewhat difficult and at times error-prone, so most mods simply require you to disable combined objects. It does not have anything to do with the culling, just the rendering, it is cheaper to render 1 big mesh then it is to render 4 tiny meshes, especially if they contain the same geometry count in the end. Disabling object culling has its own issues, especially in downtown boston, and will incur a noticeable FPS drop in a already FPS restricted region of the world. If you have the ability & option, it is best to create new PreVis files that exclude the newly scrappable objects, unfortunately this is not a option for everyone, and previs files that work for one load order will not work for any other :( TL;DR Use `bUsePreCulledObjects=0` only if your PC can handle it and you have mods that let you scrap normally unscrappable things causing previs issues.