Ya I might keep a fire extinguisher on hand
I'm not really up on those breakers. I had the same problem in a work truck and the shop added a 20 amp breaker to replace the 20 amp fuse that kept blowing. It finally burned up the wiring harness. Maybe it would have burned up with a 10 amp breaker. The circuit never pulled over 10 amps during normal operation according to another mechanic. He blamed the guy who put in the breaker for destroying the harness. Of course they didn’t like one another.
I just don't know how fast the breakers will trip as compared to the fuse. Fuses can be designed to blow at different speeds while rated at the same amps. So I would feel a little safer downsizing. Maybe it’s not needed.
One thing a bit off topic is I found that Ford now runs wire that is rated for a specific load. Care must be taken when taping off something like the radio circuit to feed other devices. Some of the electrical wires are a very small gauge. This posed a big problem in my new truck. They had to add relays and tap off the battery directly for some add ons. I'm not sure about the new 08 vans.