By hooking KeyBoardQuit on keysnail, disable caret browse mode and hide panorama with C-g. C-g means that I want to back to normal browsing.

enhanced-keyboard-quit.js

hook.setHook('KeyBoardQuit', function (aEvent) {
    if (key.currentKeySequence.length) {
        return;
    }
    command.closeFindBar();
    var marked = command.marked(aEvent);
    if (util.isCaretEnabled()) {
        if (marked) {
            command.resetMark(aEvent);
        } else {
            if ("blur" in aEvent.target) {
                aEvent.target.blur();
            }
            gBrowser.focus();
            _content.focus();
        }
        util.setBoolPref("accessibility.browsewithcaret", false);
    } else {
      TabView.hide();
        goDoCommand("cmd_selectNone");
    }
    if (KeySnail.windowType === "navigator:browser" && !marked) {
        key.generateKey(aEvent.originalTarget, KeyEvent.DOM_VK_ESCAPE, true);
    }
});