Modify the ZNet firmware to customize it

Hi guys, I need to customize my modules firmware (ZNet 2.5 OEM Coordinator API,version 1147 or later) cause there are some not described or forecast pin actions, like deactivatin the module status blinkin signal (out from the pin 13). So i suppose the only way have is to change the firmware from the inside. Can anyone help me? Do you know if this firmware is available or requestable?

The 1x47 firmware is available on the support site.