Not a direct correlation, but.....

I plant 15 inch row corn, and when not drilling soys, 15 inch row soybeans too.   I plant with a track tractor on 120 inch centers, planting 40 feet.  Spraying is a 120 foot sprayer.  Believe it or not, but utilizing a guidance system on our nitrogen applicator, I can sidedress the 15 inch row corn if I wish. 

To do all this without damaging two rows of corn, we took off the row units of our planter that match up with the 120 inch centers.   We then increase the planting rate of the rows on both sides of where the rows would have been if we hadn't of removed them by 50 percent.  This increase in population makes up for the two rows that are missing.  We use to accomplish this by changing the sprockets on the four rows involved.   We put VDrive on our planter this year, and with VDrive we're able to program our desired 150 percent rate for those four rows.  Worked real well.

One of the added benefits of this system.... sure makes it easy to see where to start the next pass with either the sprayer or sidedress applicator.  All we have to do is look for the tramlines.  No more having to count rows.  Which would have been real challenging for me with 15's.  30's were tough enough.  Can't imagine what 15's would have been like. 

To address your question.... would widening a couple of rows on your planter, necessitate having to make a corresponding change in your corn head for combining?  I don't know if it would or would not.  But probably should be considered.  I don't think you would lose much yield by widening a couple rows by 6 to 8 inches.  Sure wouldn't think so, but maybe a little. 

Those are the only two concerns I can think of.   Perhaps the benefit of what you're suggesting would be worth what little negative effect there would be with those concerns. 

gordon