Wow. From what I have read, DXO is definitely NOT parsing the TIFF structure properly. Software like this is very fragile an will break easily with camera firmware updates, etc.
I would suggest dropping DXO and switching to something where the programmers have a clue.
FWIW, I have done extensive testing with edited ARW images and the Sony IDC utility, and it couldn't care less if the data moves around in the file because it follows the proper TIFF pointers (as it should) to find the data.
In terms of the sophistication of lens aberration correction and raw development options (once it manages to read the RAW file :-) ), DxO is class-leading - meaning many of us can't casually dismiss it and find the same capability elsewhere. (My livelihood ultimately relies on delivering work my clients love, not on ease of handling the metadata in those files).
That said, Phil's point about the Sony IDC utility not having trouble correctly interpreting the DSLR-A900 ARW files which PhotoMechanic has enriched with embedded metadata, kills DxO's argument that they follow any legitimate manufacturer's standard.
I think we should petition DxO to use the TIFF offset in ARW files so the embedded metadata fields can be used. Kirk, can you weigh in on how we can precisely frame the technical point here? (I think I get the issue but would not want a not-quite-right word to undermine the power of the argument there). Then we can write the rest and push it through.