Originally had the problem of moving to purchased verrsion, but just realized that I had overlooked the email link to download the purchased version and found an answer that there is no need to include the license key.
You are correct. Once one has purchased a ShinobiCharts licence there is no longer a need to include any code which sets a trial licence key. One must however remember to download a licenced version of the library and swap this into their project. The licenced version of the library is designed to work without a licence key being explicitly set in code.
I hope this clarifies things, please post a response if it does not.