Preferred-vendor (or "program") contractors agree to the insurer’s pricing and process to stay on the referral list. That can create pressure to trim scope. It is legal and sometimes convenient, but it is not a requirement, and it is not always in your interest.
Choosing your own certified restorer means the person documenting moisture readings, category, and scope answers to you. Heartland supports your claim with adjuster-ready documentation and accurate pricing so discrepancies do not fall to you.
You can still work smoothly with your carrier - filing, communication, and payment all proceed normally. You are simply choosing who does the restoration, which is your right on every claim.