Assign / email more than 1 contact at once

Would love to be able to assign and email more than one person at a time. In addition to design, we do a lot of staging and work with relators and brokers. Often we have to email invoices to a head realtor and then also their accounting person - since there doesn’t seem to be a way to even assign more than 1 person per project, even if we add both contacts to our contacts, we then have to save a pdf to email it from gmail for example…

Would also love to be able to add multiple emails in the send field without having to add them to our contacts.

Finally - it’s so hard to quickly change out the assigned client for a project. Can’t figure out how to even add a different one unless emailing them a quote or invoice, etc, at which point I have to go delete them from contact if they already existed there (because it never finds/populates them in the send field even if they exist already), re-add them again, and then once I email them from design files they are assigned as the new client for that project. It’s too many steps/cumbersome…..