SamyGO

I downloaded both LEXXB650 (EU) vs LNXX650(USA) version of firmware.
I inspect both of it and I found big difference on file sizes.

I xored both exe.img data with python script and I inspect firmware.
European exeDSP is like 35.7 MB but USA one is 25.5 MB.
Difference is bigger than 10 MB.

AppData image is different to.
American AppData image is 34 MB since European one is 28.6

I thought that there could be minor differences between firmwares. But I found big one.
I still believe hardwares are same but software not.

It's look like their processor are same, we needed to execute US version of exeDSP to watch out differences.
I don't know executing exeDSP alone is available. Or it could be executed from NFS but worth for try.
Might be US version of firmware could support DTS.

I had similar a thought and had already downloaded the US UExxB7000 image.
It should be possible to simply copy the US exeDSP to e.g. /mtd_swu and then "mount -o bind" a different /mtd_exe/rc.local to start exeDSP from /mtd_swu.

I may have time to test it the next couple of days

Regards
dynamic