I tested this a bit and came up with this;
1. Close Chrome
2. Open "/Users/[my user name]/Library/Application Support/Google/Chrome/Local State" in a text editor. TextEdit will do fine.
3. Look for the line "macappstore": true, under "protocol_handler":
4. Delete this line and Chrome will start to prompt you to open MAS links.
5. Change the true to false and MAS links will open without prompting.
6. Save the file and Quit the text editor.
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