Towing capacity and tow ball load

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Hi seeking some advice.

The X5 seems to be rated to 2700kg towing capability but only 120kg tow ball load in all the documentation I have found to date. This tow ball load is too low for my needs. The 2700kg tow capacity is fine.
Somewhere I read that there was / is a factory option for a 270kg tow ball load towing kit that when fitted provides a factory ball rating of 270kg for the X5 - up from the stock 120kg.
I am not interested in only a tow hitch that is rated at this higher level unless the vehicle is also so rated ie for insurance reasons. For example my X3 tow hitch is rated at 150kg ball weight but the X3 only at 80kg and the lesser is "it" as far as insurance companies are concerned and thus I am seriously out of spec and looking at upgrade options.
Can anyone offer some advice? Does such a heavy duty option exist and if installed will the X5 be also rated to 270kg tow ball load.
Looking at both E53 and E70 at the present time.