Sir,
All awards over $25K require a third signature. This is in the manual M21-1, Part 5, Chapter 9.01. Some stations may require larger awards, say over $250K, be reviewed by the Director at that station.
The Fast Letter 07-19 your refer to was rescinded on 8/14/2008.
Any retro amount is not determined until the end of the process, when the award is finalized. I have on good authority that this would not cause undo delay in a claim, other than the time it would take for the third person to review it. Each claim is a new experience, regardless of what the issues are.
The third signature refers to (1) the VSR that prepares the award, (2) the authorizer that reviews it, and (3) a supervisor that does a second review. At least at the station I am familiar with. And at that point it is not a matter of changing the rating, it is making sure the amount is correct and nothing was missed.
Also, RVSR's are in a probationary status for an amount of time, depending on station policy. I know of one station that requires a second review on all ratings for up to two years after training is completed. And reviews are done after that for quality purposes. Does that mean that errors will still get through? Most anything is possible. I have it on good authority that the VA calls in files for reviews on claims, and if an error is found it is returned to the RO for corrective action.
I am not trying to start anything with you, sir, but to clarify. I am a veteran and I hope I can help clear the air.