Overview: It is sometimes preferred to default to interacting with the Web in focus mode. For example, partially-sighted people using a magnifier with NVDA may prefer to start in, and stay in Focus Mode.
Therefore, the locked-focus setting would maintain focus-mode even when opening new browser windows, restarting the browser or possibly even when switching browsers.

First, please create a key command to lock focus mode, default could be NVDA+ctrl+space.

Second: Please create a configuration file setting to lock focus mode, The user could place this in either a global or a triggered-configuration.