So if you have two systems that have near flat responses it’s possible that one sounds better for certain inputs.
Also Bose plot (frequency and phase plot) is a type of analysis that assumes the system is linear. If the system is not linear, what is the plot showing you? I imagine many systems are very close to linear, but at the edges of dynamic range they can’t be.
So you need to pick from different non-flat speakers, which means listening test if you really care. You can't figure out which one you'll like just from looking at the frequency response graph.
This is not theoretical, I've experienced it - two professional speakers (or monitors as they are called) from different manufacturers, which cost the same and the frequency plots look the same to a human eye if you put them side to side, but sound very different.
Which is why it's preferable to listen them if you really care. But there are "safe" recommendations for every price range.