I have a crank that uses a four-arm spider, like Camagnolo Record, except it's on a Shimano system with Shimano 130 mm BCD. I just found out that Shimano rings are supposed to be oriented so that the peg (big ring) and the little notch (small ring) are in line with the crank arm. I cannot do this since it would be offset due to the chainring bolt orientation - the fifth bolt is in the crank arm instead of the crank arm being between two different bolts.

Should I put the peg/notch offset "ahead" or "behind" the crank arm? Right now I have it 180 deg from the crank arm because I thought it looked best that way. But I think I'm getting ghost shifts because of it.

Or should I really get rings designed for such a crank?

It looks like this:

Pretty cranks!

I don't think the position will really matter in terms of shifting performance. The real bummer is that peg is intended to keep the chain from wedging down between the crank arm and the ring if it falls off, and it won't work in this case.

Shimano says that the ramps and pins on the rings are oriented to ensure smooth FD shifting and that they are positioned specifically to engage during a certain part of the pedal stroke - thus the orientation technically does matter (according to Shimano anyway).

It could be BS.

Yes, but it's not critical.

Shimano FDs do not offer as much upward motion in an upshift as they used to; they more push the chain rather than lift it. The ramps and pins are to assist, and as long as the two rings are aligned their position on the crank arm is not critical.

It's not like you shift the FD with the crank in the same position every time; it's in motion.