That part confuses me. Your primary care provider (PCP) should not see you are on Marketplace plan. They should only see BCBS. Are they dropping BCBS customers?
That also confuses me as BCBS is the gold standard for many providers. It is also the top Medi Gap provider which is something you need to consider next year versus an Advantage (part C) plan.
Talk to an independent broker as others have recommended. If they talk only a Medi Gap and don't talk Advantage, go find another one. If the next one only pushes Advantage, well that sucks, too. Agents are commission based, but they are required by state insurance laws to present all options. However the dollars speak louder unless you push them
The only one that I remember with a 1 time choice is part D or prescription drug coverage. You can option in or out. But if you option out today and decide to enroll later, there is a penalty.