Especially after failing to treat gout for many years, flushing out uric acid can take a very long time (possibly several years).
Diet-wise I would recommend avoiding all diuretics (not just beer), drinking a lot of water and eating foods containing a lot of minerals (such as most vegetables).
I really can’t venture an opinion with regards to your allopurinol dose based on the limited information you have shared. I can only say that, if your SUA test results (notice the plural) are under 300 umol/l, your current dose is serving you well already.
If you have OA at the typical locations where you get gout attacks, your symptoms must be confusing.
It is unfortunately next to impossible to tell gout symptoms suppressed by colchicine and naproxen from other problems, except perhaps by drawing sinuvial fluid which isn’t the most reliable of procedures. And for the time being, I would not recommend you stop taking drugs to suppress inflammation whenever your symptoms look like they are flaring up…