IPIX only needed to meet 1 of the 6 transaction requirements to register and your referenced 1.B.6 didn't apply because they weren't on a national exchange. We could dig further into the instructions of 1.B.6, but there's really no need.......
1.B.6 Limited Primary Offerings by Certain Other Registrants. Securities to be offered for cash by or on behalf of a registrant; provided that:
(c) the registrant has at least one class of common equity securities listed and registered on a national securities exchange.
Leo didn't address your question because he doesn't report to you. I've seen many biotechs under $75M MC able to raise money with public offering after filing S-3 (see Celsion as an example).
IPIX's current priority is to partner B-OM. If successful, either the partner will pay for Phase 3 or IPIX will use the upfront money to advance B-OM and B-ABSSSI into Phase 3.