I pretty much approach finding accurate ammo for my airguns, the same way I did for my powder burners back in the day. As a hunter, I'm looking for that one most accurate pellet in a given rifle. I don't need three, or five, I just need one. The most accurate one.
When I was heavy into varmint hunting with my powder burners, I would search for the one exceptionally accurate load for any given gun. Load development consisted of trying different powders, primers, and bullets, until I found that one load that would shoot bug holes at 100/200 yards.
I would work up loads, by increasing the powder charge in one or two tenths of a grain increments. I would turn case necks, uniform flash holes and primer pockets. Experiment with bullet seating depth, and check the loaded rounds for concentricity on a concentricity gauge.
All of this was done to eliminate variables, while searching for that one load that was more accurate than any others. Once that was found, that became the load of record for that specific rifle. I didn't start looking for a second or third load, I had the one I was looking for, and that's all I needed.
With my rimfire rifles, I would try different brands, and types of ammo. Invariably, one brand and type would shoot better than the others. I would then try and buy as much of that load's lot number as I could find. Knowing, that the next run of the same ammo might, or might not, shoot as well as the one I had tested.
It never crossed my mind that a particular rifle was, "load picky" because it wouldn't shoot a bunch of different loads, or brands and bullets equally well. I knew it was pretty much a given that it wouldn't, and it was up to me to find the one load the gun would really shine with. Were there exceptions, of course, but they were just that, an exception not the rule.
I approach my airguns in the same way. I don't expect any of my guns, no matter how expensive, or inexpensive they may have been, to shoot more than one pellet exceptionally well.
I don't go into accuracy testing with any specific brand expectations in mind. I am simply looking for the most accurate pellet, that a specific gun/barrel combination will shoot, at the distances that I will typically be taking shots at. The specific gun I'm testing will tell me that. If it's brand X or brand Y pellet, doesn't really matter to me. The most accurate pellet in a given rifle is what I'm after, and that's the bottom line for me.
Once an accurate pellet has been identified, I'll start fine tuning the process by weight sorting the pellets, and experiment with how they shoot lubed or unlubed. I've tried sizing pellets, and for my hunting applications, I've never found it to be worth the time, plus a choked barrel pretty much takes care of that issue at the time the pellet is sent down the bore.
I never consider a particular rifle, pellet picky because it only shoots one particular pellet extremely well, because that's actually my goal, to find that one pellet that the gun shoots better than any others. Just like with my powder burners, once that accurate load, or in this case, accurate pellet has been found, it becomes the designated pellet for that rifle.
I also buy pellets in lots of five or ten thousand . Just like with rimfire ammo, the next run of a given pellet may, or may not, shoot as well as the ones I have on hand.
So "pellet picky" isn't something I even think about. The one most accurate pellet, in a given gun, at the distances that I typically shoot at, is what I'm looking for, and once that has been identified, the hunt for the most accurate pellet is over, and the hunt for critters is on.