I think it's worth distinguishing between "shell" browsers that simply wrap an encapsulated rendering engine (such as those IE6/MSHTML-based browsers from decad

I think it's worth distinguishing between "shell" browsers that simply wrap an encapsulated rendering engine (such as those IE6/MSHTML-based browsers from decades ago) and other browsers like Chromium/Edge/Opera which have a different level of integration with the rendering engine - because those browsers are able to tweak and extend - or disable - the engine's features on a granular scale. It's better to compare Chrome/Edge/Opera as "distributions and customizations" of Chromium/Blink instead of mere as wrappers - the same way that Linux distributions aren't reduced to just "GNU/Linux kernel wrappers".