Software license upgrades involve upgrading of the software code. We do not outline any expectations for it, however you can check out the "What's New" page at https://www.ultimatewb.com/whats-new for a list of upgrades we have done and what they have included.
As your website grows, you will need more server resources.
Purchase of the software license allows you to use the software for your designated domain name. You can use the software to create and configure/customize your website and features, and also choose to add your own custom coding to your website. If you do choose to add your own custom coding, you can then modify that code as you would like. The software code itself is not available for direct modification.