I did mention this on some main idea's thread. We can all relate, that there are issues with the placement and fences handing in air and so on! Happy to see someone else eager to change it! :)
You can use the console code, seems to work with some. You can lower items when holding E and use the mouse wheel. I know that there is console code for the player itself like noclip, but I don't know for the items themself. Do you perhaps know..?
Is it possible to remove the collision between two items when building settlement? Its annoying that I cant get two junk fences act normally next to each other. Some even don't align with ground but often hang in air, so it would be possible to lower them into the ground a bit.