Currently there is just one set of defaults, but I could very well add multiple different defaults dedicated to certain use cases such as the ones you have. I imagine it'd be something like this

bef -c --default share -i input -o output, bef -c --default dvd -i input -o output, bef -c --default tape -i input -o output, etc.

It seems like a good idea and wouldn't exactly be hard to implement.