Hmm. I've never had to actually delete the vectors from the back side of the sheet. I manufacture the parts for a combination drum/case that has a lot of machining on both sides of the panels. I label the layers on the top as "A-layername" and the ones on the back as "B-layername". If I need to make a change, moving from back to front is as easy as selecting everything on that side and doing a "Move to other side". To move the other direction, I turn off the "A" layers, make sure the "B" layers are all on, select everything and "Move to the other side". No deleting, which would make me very nervous. When you make changes, you do need to make sure you're working in the right layer so things don't get messed up.
D&S Artistic Woodworking http://www.dsartisticwood.com