My private.xml file for Karabiner - Logitech R800 remote presenter settings for Apple Keynote (this remaps the blank/show screen buttons so they don't quit the slideshow)

private.xml

<?xml version="1.0"?>
<root>
  <devicevendordef>
    <vendorname>LOGITECH</vendorname>
    <vendorid>0x046d</vendorid>
  </devicevendordef>

  <deviceproductdef>
    <productname>LOGITECH_R800</productname>
    <productid>0xc52d</productid>
  </deviceproductdef>

  <appdef>
    <appname>IWORK_KEYNOTE</appname>
    <equal>com.apple.iWork.Keynote</equal>
  </appdef>

  <appdef>
    <appname>POWERPOINT</appname>
    <equal>com.microsoft.Powerpoint</equal>
  </appdef>
  
  <item>
  <name>Logitech R800</name>
  
    <item>
      <name>R800 For Keynote</name>
      <identifier>private.R800_for_keynote</identifier>
      <only>IWORK_KEYNOTE</only>
      <device_only>DeviceVendor::LOGITECH, DeviceProduct::LOGITECH_R800</device_only> 
      <autogen>--KeyToKey-- KeyCode::DOT, KeyCode::B</autogen>
      <autogen>--KeyToKey-- KeyCode::F5, KeyCode::B</autogen>
      <autogen>--KeyToKey-- KeyCode::ESCAPE, KeyCode::B</autogen>
      <!-- autogen>--KeyToKey-- KeyCode::PAGEUP, KeyCode::BRACKET_LEFT</autogen -->
    </item>

  </item>
</root>

My R800 had a different productid. Was able to find mine via About This Mac::System Report...::Hardware::USB:::USB 3.0 High-Speed Bus::USB Receiver