This is how i dogear alsoI could do with a vid on how to mod a standard channel as i was thinking the same, wonder why people don't have issues on a modded standard.
First cut 45° angles on the ends with a vice or workmate and hacksaw
Then file edges smooth
I also file the underneath of the channel where it is cut a couple of mm shorter to avoid scraping
Then dogear like this
[media]http://www.youtube.com/watch?v=FuWbfKzFog0[/media]
Then cut rubber like liquidators
[media]http://www.youtube.com/watch?v=uC9DXeVYP0Q[/media]
I'm showing Bobs vids as i can't be arsed to do my own