[DNSB]

If you change the title or author, that would require a delete and resend since those would look like new books. For series and other metadata, you should be able to connect your Kobo to calibre and the updated metadata will be updated automagically if you have Metadata management set to Automatic management under the Sending books to devices preference. Otherwise, metadata will be updated when you send a book or you can update cached metadata. One exception is if you are using a metadata plugboard to add the series information to the ebook title in the library or using the Save template to change the filename sent to the device in which case, you are back to the delete and resend.

I would recommend using NickelMenu and configuring the USB connect option so you don't have to unplug/replug as often.

You could also look at the Reading List plugin to automate sending but again, since a book with a different title or author would look like a new book, you would have to manually delete the old version. Possibly connecting your ereader, select show books on device, sort by In library to show books on the device but not in your calibre library would be useful.