Thanks @JColvin!
I put some of the original numbers into a spreadsheet here, re-ordering the pins from alphabetical to numerical.
Some questions:
* Each pair has up to +/- 1.2mm delta, I assume this is within spec (which spec, heh) or accounted for by extra trace length in the FGPA?
* Looking at these totals, I assume that each differential pair is only length matched as a pair and not for all pairs in the high speed PMOD port? e.g. if I have two differential data lines clocked to my differential clock, I’ll have to add some serpentine routing to the shortest pairs.