Can I switch from owner FR44 to non-owner if I sell the car?

Yes, if the car is actually gone and you are not replacing it. Sell it, total it, give it back to the lender... then a non-owner FR44 can keep the filing alive without insuring a vehicle you do not have.

The dangerous part is the handoff. If the owner policy dies on Tuesday and the non-owner policy starts on Thursday, the DHSMV can see a gap. We've talked to people who thought a two day hole would not matter. Florida can treat that hole like a lapse, re-suspend you, and the three year clock can reset.

So we line up the dates. Cancel the owner policy and start the non-owner on the same day. We shop 15+ carriers and file electronically so the state keeps seeing an FR44.