I recently emailed the contracting officer on an open federal Request for Proposal (RFP) for IT services, NAICS 541519. It was a small business set-aside. I wanted to ask if a partial response would be acceptable because our past performance was strong in some areas but not all. The deadline for questions had already passed, but the submission deadline was still a few weeks out. The CO replied with a one-liner, just pointing to the Q&A deadline. It felt like a brush-off, but I understand they have rules.
What are the rules about what a contracting officer can and cannot tell us during an active solicitation? When is it appropriate to email them directly, and what kind of questions are generally welcome outside of the formal Q&A period?