Regular maintenance

General consensus is 15 hours on a piston is too low. Personally i dont trust cast pistons. I wouldnt run them more than 15-20 and if i buy a used bike i immediately replace them with a wiseco one and run it for 40 or so. I do pistons once maybe twice a year with a 3 hour ride day 3 times a month & riding season only lasting 6 months here in ohio...

I do oil changes every 3 rides. I only use maxima full synthetic.

Chain/sprockets get replaced when they need it. Adjustment is checked after every ride

I think the recommendations are for a full on race bike. Remember, they don't have slow guys, vets or pro practice riders torture testing these bikes and they do torture test. They do full tear downs and measure every last component to check for wear.
It doesn't really matter how many "rides" you put in because everyone is different. If I rode desert all the time I would probably change every ride as I would likely have 6-8 hours after a weekend of riding. When I moto, I rarely put 2 hours on my bike. I also don't peg the rev limiter or hammer my clutch.
Do you have an hour meter on your bike? I have a 17 FC450 and the manual calls for an oil and filter change at 10 hours, piston and rings at 50 and major rebuild at 100 hours.
I changed my oil at 3 hours after break in and then at 10, 15 and am due now at 21 hours. I was out for 3 months or I would have easily double the hours I have now.
An engine oil analysis would be a good indicator of engine health and quality of oil and would let you know long you could run on an oil change.