Thank you for your new purchase and exciting to hear that you want to upgrade! 

Regarding your question, it is possible to add the Dirac Live multi-channel license option to your miniDSP Flex HT. The cost for this option is the same as if you had requested it during the initial purchase of the product.

To add the Dirac Live option, please use the Dirac Live upgrade from our Device Console as per the manual:

From there, you can select the Dirac Live option and proceed with the purchase. Once the purchase is complete, your device will have ability to support Dirac Live.