It has been a very long time since I have had to deal with this issue, but years ago I do remember that any edit to negative would in fact destroy the adjacent frame. This has to do with the way the film is cut to be glued together by the negative cutter.
The whole idea behind electronic editing tho is to avoid having to remake edits to camera negative. You are supposed finish all the editing and revision BEFORE you take a blade to the film. Even tho the frames are lost at the splice, you never see them because it is the frame before your incoming shot, and the frame after your outgoing shot.
That all sounds like I know more than I actually do. If you are going to have your film conformed to your cut to finish I would think it a wise investment to buy your negative cutter lunch and pick his brain early in the process.
-Vance