Brave's default PDF viewer is not compatible with some extensions


I am very happy that Brave has moved to Chromium, as it now has almost all the functionality I need. One major obstacle for me though is using Brave with Readcube Papers, which I use every day to manage, read, and annotate my library of academic papers. The issue is with the incompatibility between Brave’s default PDF viewer and the Readcube Web Importer extension. In Chrome, a paper can be opened in Chrome’s built-in PDF viewer and then imported directly into my Readcube library using the extension. As far as I can tell this is not possible with Brave’s default PDF viewer, which appears to be this one from the Chrome store (

Probably installing the Chrome built-in PDF viewer in Brave would solve this issue, but I can’t see any way of doing this (I suspect this is Google’s own tech). This is a relatively minor issue but since I use this extension every day I have ended up doing all my academic work in Chrome, and all my other browsing in Brave; kind of annoying. Any chance of an update to Brave’s default PDF viewer? Or does anyone know how to install the Chrome PDF viewer into Brave? Does anyone else have similar extension compatibility issues?