Granted there is an AUX tank for 135 and 145 but if you do the numbers and research, neither system is very practical.
You tell me :-))) But you now, these choppers does not fly so well without fuel.
I will look in the fenestron structure if there is something, and try to order nose trim weight. Cooperation with Eurocopter is disaster. It took me several months just to ORDER aux fuel tank instalation. The company reminds me of Franz Kafka book Castle.