Backtick as a non-dead key?
A keyboard layout called Belgian2 with the backtick you want can be found at this page.

Install the .keylayout file (remove any .txt extension if there is one) in Home/Library/Keyboard Layouts.  Then go to System Preferences/Keyboard/Input Sources and use the plus and add buttons to activate it (look in the Others folder).  Then select in the "flag" menu at the top right of the finder.

To get to Home/Library, you need to hold down the option key while doing Finder > Go.  You can also install in Library/Keyboard Layouts to make available to all users.