I'm not quite sure I understand what ye mean by sharp edges
If a quality mini bolt cutters is used its a silky smooth cut.
The main advantage I would have always thought to putting the wire on the inside is that the birds can not attack the actual wooden structure, I've my Sennie's in almost a week now and I had an unwanted retaining board left pinned to the wall and its gradually being ate away.
Also having the board exposed on the outside makes it very easy to clean right into the corners - I use a mini-hoover so I never have to go into the aviary with it but I get all the seed husks hoovered up.
Guess everyone has their own method
