Seems like you can upgrade from what I read, you just have to follow a set progression to do so successfully. Just upgrade from your current version to the 1.1.1.x version and then follow the progression. Just be advised you'll lose your configurations.
according to the instructions:
Caution:To successfully update the firmware to v2.0.6.x from v1.1.x.x, you must perform a series of updates in the following order: V1.1.1.x.rom > V1.1.50.39.rom > V2.0.0.16.img > V2.0.0.16.bix > V2.0.6.x.bix
Caution:Existing configurations will be erased after updating the firmware from v1.1.1.x to v2.0.0.x. Furthermore, configuration files are not compatible between v1.x.x.x and v2.x.x.x firmware.
