As expected, Logitech has refused my request to provide the source code of the X-Plane plugin.  So, there is nothing I can do about it from this end, but I will continue to look for other options, if there are any.

Will I continue to develop FIP gauges for X-Plane, some asked?  Probably when timing is right, because not all aircraft involve the using of fuel flow in the way as the C172SP does.

Update: A Rally on XPlane C172 Fuel Flow Issue – Help Wanted