While your uric acid is indeed very high, not all people will develop gout. The normal approach would be to start medication after a gout attack.
Some rhematologists would say start medication after a single gout attack, some would say if you get two gout attacks within a calendar year however I am no doctor and the doctor you see may very completely in opinion.
I started medication after the second attack and looking back it now, had I known what the pain would be like, I wouldn’t even wait for the second attack and would have started it after the first attack.
On another note, a low purine diet is highly unlikely to bring your uric acid levels down alone. 9.6 is exceptionally high for diet alone treatment. Again I am no doctor.
My opinion would be to either discuss further treatment options for your high uric acid with your doctor or maybe see a specilalist rheumatologist.
Gout is an insidious disease and creeps up on you over time but not everyone with high uric acid will get it.