You've got a couple options -
1. See if your PCM can address this in the VA NARSUM Addendum
2. Once the ratings come back, sign the option for a VA recon and have them re-review their report, and you could also submit an independent ROM if you had one done as evidence that there is inconsistencies.
Once your ratings do come back from the IPEB, make sure to speak with the OAC (attorney) before signing. They will give you the best counsel.