A B-1 is NOT a substitute for an H-1B. There are very limited activities that can be performed on B-1 visa entry. They are not the same as those that can be performed on H-1B. You need to verify with your sponsoring company's attorney that the proposed activities can be legally performed while on B-1. Beware of having your employer encourage you to participate in unapproved work activities while the RFE is in processing since any violation of the rules affect your future in the US. You can be denied entry for unauthorized types of work activities.