At the moment users have only the option to either always use the master file, or every time they create a new project choose a new file. These are two different flows, and should be reflected as such.
Additionally, study the option of saving the information needed using Burp's saveExtensionSetting and loadExtensionSetting capabilities (might work and usage of the state files would be deprecated and only used to actually export the results when needed).
At the moment users have only the option to either always use the master file, or every time they create a new project choose a new file. These are two different flows, and should be reflected as such.
Additionally, study the option of saving the information needed using Burp's saveExtensionSetting and loadExtensionSetting capabilities (might work and usage of the state files would be deprecated and only used to actually export the results when needed).