Chris, the SFF D2700 shelf itself supports 6G and 12G drives. The drives that are currently sold and qualified for the MSA 20xx, in the D2700, are all 12G drives. As per that document, 6G drives are not supported in the MSA 2050, regardless of what enclosure they are installed in. If you'd like to private message me your e-mail address, I can take this offline and see if I can connect you with your local HPE account team who may be able to help you with this further.
Thanks,
Mike