There still seems to be a bit of confusion on how the difficulty level works on BitcoinV. The difficulty is split into two areas:
1) The original Bitcoin difficulty level
2) Variable Block Reward difficulty level

When mining at x1, BitcoinV is the same as Bitcoin and the VBR difficultly adjustment does NOT kick in. When mining at x2 or larger, the VBR difficulty level kicks in. Changing what the GBT reports for difficulty would make a miner waste its power by trying to find a block with more zeros than is required. Once there have been enough leading zeros found in the hash (original Bitcoin difficulty level) then the VBR difficulty level kicks in where pattern matching of Merkle root with previous hash. Just a note, many pools are using greater than x1 and properly paying the rewards...