Vlad Hmmm... Doesn't seem like it -- with a caveat.
For example, I can rebind it to CMD+P (print); but it seems like hitting CMD+P still opens the print window. Same for CMD+J (downloads), CMD+Y (history), CMD+F etc. But the extension accepts it; it just doesn't trigger it to open the extension.
I am unable to rebind it to CMD+T and CMD+N; that's being refused altogether.
Not sure if that's an idea -- working with a type/leve lof shortcuts? Primary, that can't be modified, and some that aren't as useful, that can be overwritten?