When making test strips for split printing the order does make a difference. When making the final print the order makes no difference.
In high contrast prints (#5 exposure > #00 exposure) the #5 shadow exposure effects the highlights, but the #00 highlight exposure has little to no effect on the shadows.
In low contrast prints (#00 exposure > #5 exposure) the #00 highlight exposure effects the shadows, but the #5 shadow exposure has little to no effect on the highlights.
So, for high contrast prints make the #5 test strip first to determine the shadow exposure, then make the #00 test strip to determine the highlights.
For low contrast prints make the #00 test strip first to determine the highlight exposure, then make the #5 test strip to determine the shadows.
This is the reason for the perpetual debate about which test-strip filter to use first. Those who develop/shoot high contrast negatives swear that the #00 test strip must be done first, and those who develop/shoot low contrast negatives state with equal conviction that the #5 test strip must be done first. They are both right and they are both wrong.
See the application note on split grade on the Darkroom Automation web site http://www.darkroomautomation.com/su...sgmeasured.pdf, starting on page 3 "HOW SPLIT GRADE WORKS"
What Nicholas wrote makes sense to me. My negatives have been evolving to fit my printing.. with longer development times, just as he says.