I would love to have the save and add button seperated from the 'save' and drop down menu button in the invoicing section. I have no idea why one would like this merged with the save button when crea...
I agree, a lot of us will be processing multiple invoices at once so having the 'Save & add' button easily accessable is needed.
The other option is to have the 'Save & Add' option as the default instead of just 'Save'. Those who only want to record one invoice can still use this option (or use drop down menu to select 'Save') and then they can click on whichever screen they wish to use next.