Were you able to activate the second license? Here's how to activate a different version. There is a way to have 2 licenses. Under Help - Switch Product - Activate new product. Don't know what that will do or what benefit you will get. Don't think it will allow you to efile more than 5.
IRS Publication 1345, Handbook for Authorized IRS e-file Providers of Individual Income Tax Returns page 31, https://www.irs.gov/pub/irs-pdf/p1345.pdf
#5. Ensure that it doesn’t accept transmission for more than five electronic returns originating from one software package or from one e-mail address
The 5 efile limit is from the IRS. It's to prevent fraud and people filing fake returns. To do more you have to sign up as a ERO - Electronic Returns Originator and be an authorized E-file provider.
https://www.irs.gov/e-file-providers/become-an-authorized-e-file-provider
