Hi
I am not an expert but everyone say that the tailgate can not even hold the stock tire. If you look in the manual it states "If you have added aftermarket accessories to the
spare tire mounted carrier, it cannot exceed a gross weight
of 50 lbs (23 kg) including the weight of the spare tire" and a Rubicon wheel weigh more than 50lbs. It is sad that the tailgate is so weak. There should come real mounts for a jerrycan somewhere at the back from the factory. Some that have diesel vehicle have diesel jerrycans in the vehicle because diesel is less dangerous. As the tailgate are flimsy, why dont anyone offer a bracket for a rotopax or similar to be mounted under the vehicle, that would be a great solution, could also carry water that way.
If You look at many pictures You se offen that they also have a tire rack carrier that support the weight but offen dont mension it in the text