Ah, I see. Sorry for my confusion. 
I think a lot of the shortcuts work as youād expect (like select-all, bold, copy, and paste etc), though the hyperlink one does open the modal. I donāt believe there is a way in the settings to disable that, though Iāll check to make sure.
There is a quick āinsert linkā that may be of some use. If you copy a link from somewhere and then highlight the text in your composer youād like to make a hyperlink, you can then paste your link in and it will automatically format it as a markdown hyperlink with the highlighted text as the display text.
Thereās also the inline onebox approach too, which can be quite useful, where just pasting in the link into the composer mid-sentence will add a title where it can. eg Plugin directory | Discourse - Civilized Discussion .
Turns out I did not have a handle on this topic at allā¦ 