I thought that the dumped voices pack is "unique", i.e. it doesn't come with stock EU bikes. If it does come, then you're right.
I see that HWID712 uses sys.bin instead of fw_all.bin and it's a 2009-2010 navi model. I don't know how to flash it with voices, as I don't know how to find the proper boot.bin.
Also maybe voices are present as VPM files, what do you think?