When I use Chrome on MacOS High Sierra (10.13.2), I use the “Services” part of the context menu. I highlight some text, and ‘right-click’. “Services” are “Send to Bear” and “OmniFocus 2…” You can adjust them in System Preferences -> Keyboard -> Shortcuts -> Services. I assign keyboard shortcuts to these, and it allows me to quickly interact with other apps through Chrome.
This is what I see in Brave (0.19.134):
So I surmise that “Services” aren’t supported. Not that big, I’ve got work arounds, but would be helpful. Looks like it was asked for here: Brave with Mac "Services" menu?
Woulda included more images were I not a new user. Love the browser!