I found two ways to work around this.
1) For my accounts with <150 lot transactions, after importing the OFX from the broker, I manually deleted each of the generated g/l adjustment forms. The reported 1099-B totals from TurboTax and my broker then matched to within ~$1.
2) For accounts with >150 lot transactions (too many for me to individually delete), I downloaded the CSV list of transactions from the broker and generated a TXF file with my own software that rounded off the cents. Importing that rounded TXF avoided the generation of those hundreds of g/l adjustment forms. I then manually adjusted a few of the transactions to make the totals match. Not ideal, and it only works if you can code and are using a desktop version with TXF support.
