Blade pickups are a viable alternative definitely. Consider early 8-string custom shop guitars that used the EMG 45DC pickup. It was made for 6-string basses, but since it uses blades and not poles, there was no issue with strings of an 8-string guitar needing to line up appropriately (the 45DC is basically an EMG-85 in an extended housing).

In my opinion, blade-style pickups look better on 8-strings than open-bobbin pickups. All those pole-pieces in a row look kind of funny. I saw a picture of an old Conklin 8 or 9 string that used 2 6-string open-coil humbuckers together in a P-Bass-like config and it looked ugly.

 

Thing is that some people question the EMG's ability to bring out a versatile palette of sounds. Now, I don't know whether this has to do with the fact that it's a blade-pickup, or if it's an EMG, or anything other than the blade-configuration.
So, the concensus of the question is - given custom winding, can the bladepickup be as versatile, punchy, smooth and whatever else as a polepiece-pickup?

 

Blade pickups help with keeping the output the same when you bend the strings

EMG pickups help with low tunings because of their extended frequency range and clear open sound. People say they are a bit sterile but it's all preference.

 

I personally dislike EMG's, but if you'd get some passive custom bladepickups, I assume the tonal issues would be redeemed with the desired results.