The plugin has 5 main ways to display a notice. For each notice display rule, you can define extra CSS class that will be added to the notice, and allow you to better style the notice. If you choose Notice as a display method, you can also select the Notice variant to use, based on the notices supported by the bbPress (default, info, important, error or warning). Notice contains title, and by default, title is displayed with some display methods (fieldset and callout), but you can force title display with the normal notice display methods.
Basic notice rendering is based on the bbPress core styling if you use Notice and Fieldset bbPress methods. In these cases, visually notices will be the same as the once generated by bbPress. This also means that if your theme is changing the styling of these elements, it will affect the notices generated by GD Forum Notices Pro plugin.
And, because of that, plugin generated notices are compatible with the forums using GD Quantum Theme Pro for bbPress.