Actually your manual is the very same as my owner manual. It shows the oil and filter change interval at every 6000 miles, NOT 9000 miles and NOT 15,000 miles. Where do you see that? Your screenshot doesn't show that. Be sure you are looking at the "x 1000 mi" row at the top.
For the initial break in period the manual does show to replace the oil and filter at 600 miles, then just the oil (not the filter) at 3000 miles, then oil and filter at 6000 miles. Then to change both every 6000 miles after that. This is actually what has become normal for modern motorcycle engines. In fact, some motorcycle engines call for longer intervals AFTER the initial short intervals. So you are not skipping any oil change intervals.
BTW- the first few years of the Euro 4 versions of the AK did call for much shorter oil/filter change intervals but then changed in 2021 after figuring out how the engine was performing. Those shorter intervals were excessively short. Changing oil at shorter intervals won't hurt anything, but is not at all necessary.
I use full Synthetic 4 stroke motorcycle oil and the OEM HifloFiltro oil filter HF164 (which is the same filter used on many BMW motorcycles). I have the BMW filter tool, a cap style wrench, to make replacing the filter easy without removing ANY plastic including that bottom panel. The oil I use is certified JASO MA2, which IS a requirement for any bike with a wet clutch like the AK 550 (and all my previous GW, Burgman 650, ST1100, CTX1300, another Burgman 650). Don't use any oil that is not JASO MA or MA2 certified or you will eventually mess up the clutch.
This summer I'll be coming up on 12,000 miles so that means the next oil/filter change for mine as well as the CVT belt replacement. Kymco calls the CVT Belt the Drive Belt and the final drive belt that runs to the rear wheel is called the "Timing Belt (Drive Belt)." I already ordered the CVT belt from TBS and also already have an air filter. I usually check the air filter and then decide if it needs to be replaced. From the look of the air filter last time I checked it (6000 miles) it won't need to be replaced but that is different for everyone, where you ride, etc.