Hello; 

You provide a recent update for emulation (below).
--The plugins can be configured for several settings. 
--Most of these settings are stored in the $(NPP)\plugins\Config\PreviewHTML\Settings.ini. 
--Emulation | Installed IE version indicates the maximum version of IE than is supported. 
--Useful for IE10, which is not properly recognized.
I have abandoned IE and use Firefox or Chrome.
Is it possible to emulate the "default" browser or are you limited to IE?  

Thank you for your work,
Mike

I'm afraid the plugin is limited to IE. There is no way to 'embed' Firefox or Chrome (or, for that matter, Edge) into another program.

Technically, it is possible to ship _a version of_ Gecko and/or WebKit, the rendering engines of Firefox resp. Chrome, but that still wouldn't be the same version as the browser.