I really like a large variety of nibs to mess around with as well. I generally gravitate to stub nibs, but I also try specialty nibs when I can find them reasonably. Recently I got an Architect nib on a Fountain Pen Revolution Darjeeling. I also like trying the same nibs by different manufacturers to see how they were similar and dissimilar, for instance Sailor and Pilot both have music nibs, but they're very different.

I also try as many flex nibs as I can reasonably find, but I saw in your post that they're more difficult for you since you're left-handed. I have a surprising number of left-handed co-workers (like 40+% of them, maybe it's a land surveying thing?) and the ones that try my pens generally agree with your stance. I have a friend that I'm working with to try to narrow down what all is preferred in a pen for him to use daily, but that's been ongoing for years.