Godin, there's a slight gaps in your logic.
Raising the two middle poles won't make your tone more middy. What they'll do is make those two strings get picked up more, ie. make them louder. A mid-range EQ boost is a much different beast, which can and will affect ALL your strings and notes in varied and subtle ways. A note's fundamental may not be in the mids, but it may have harmonic contents in that frequency zone, which an EQ will also alter.
Plus, due to the nature of the guitar (the strings being divided mainly into intervals of 4ths), there is a LOT of note overlap. The same note can be played on different strings, as you know. The same note on the B string, for example, won't have the same middy boost as the one on the G with its raised polepiece.
I suppose if you want this unpredictable variety, that's a reason to do it. But not for mid boost. Most people will adjust the polepieces for, as mentioned, improving string balance, not for detracting from it.
Greg