Nearly all pipe clips require the pipe to be positioned, the clip
positions marked, then the pipe removed, the clips screwed in, etc Like
these https://www.toolstation.com/shop/p72747

You can get nail in clips that have the nails offset, so that they can
be nailed with the pipe in place. Like
https://www.toolstation.com/shop/p19689

Why not the same design for screw in clips? I know you can get saddle
clips, but that's two holes and plugs, etc.