Many non aviators and even some aviators do not understand that some of us use an aircraft as many use a motor vehicle. That is we do not plan an exact itinerary in advance.
I was flying up the coast in my longranger and decided to call in to the Gold Coast airport to buy lunch. Atc asked why I had not filed a flight plan. I explained that I had only decided 15 minutes before to call in.
Same in the C208. I have landed at lots of great airports after a last minute decision to do so. Met some fascinating people this way.
I will I’ll keep away from Gympie and advise others to as well until this restriction is removed.