aac+ could be implemented in software. Of course it will never be implemented in original image, because the open source implementation maybe is in violation of the AAC+ patents. Similar to software DTS downmix that is already implemented in PLI, this could also be implemented, at least for VU Duo (VU solo doesn't have the FPU performance for software decoding). BCM7335/7325 doesn't suppport AAC+ in hardware decoder. BCM7405 does.
You could request your content provider to switch to AAC instead of AAC+. The improvement of AAC+ is negligible when it comes to tv transmissions. All equipment that has AAC+ support can be switched to AAC.