"
Can I simply print and mail the 4th return instead of e-file?"
Yes.
With the desktop (CD/Download) software, you can only e-file returns in up to three different states for each federal return you prepare - the rest need to be paper-filed. TurboTax Online allows you to e-file up to five state returns per federal return.
See https://ttlc.intuit.com/questions/1899266
