I don't know if there's an easy way to drop the comma, but in case there isn't, you could create a custom column build from other columns behaving like tags, then give it this as a template
Code:
{author_sort:'re($, "\,","" )'}
The same template you could also use in a plugboard to send the books using this format for author name to your device.
This way you don't need to jump through hoops editing or renaming authors and leave them as they arrive in metadata