Does MuLogin support customizing startup parameters and loading local plugins?

Support.
1. Manually add custom parameters to a single configuration file:
Edit the browser configuration file -> Other Configuration -> Customize startup browser parameters -> Add your own required startup parameters -> Save.
For example: --load-extension="C:\Users\MuLogin\my-Plugin"
The browser automatically adds the plugin when it is turned on.

2. Automatically add custom parameters to newly created configuration files.
System Settings -> Preferences -> Customize startup browser parameters -> Add your own required startup parameters -> Save settings.
This browser parameter will be automatically added to the newly created configuration files. For old browser configuration files, you need to set this parameter manually according to the first way--Add this parameter in a single configuration file.