Take a step back. Using Table B on the Extralite spoke length site, you need the 3rd column for 32 holes, and this gives a disc-side spoke length of 292mm. That matches your calculation. Not sure where the 297 number you got came from, unless you're reading the 2nd column which is for 28 holes/spokes. Using Table A on the same page, you need the 2nd column for the JF hub (column 3 being JL=Lefty), and this gives a "right" side of 287mm. I agree "right" is a confusing term to use, but there are a few clues to clear things up:
1) Table B refers to Disc side, so Table A must therefore be non-disc
2) Table A says "Radial Lacing" in the header... no one in their right mind would radial lace a front hub on the disc side, so the side in this table must be non-disc
#2 Tells you the source of your confusion: Extralite are proposing that you radial lace the non-disc side of your front hub, whereas you calculated a length for 3x. The radial lacing has a shorter path between rim and hub so their length is shorter. Up to you if you want to follow their suggestion or stick to 3x on that side. I can't imagine it's going to make a very noticeable difference to anything except the spoke length.
Thank you. All cleared up now. I was thinking when they mentioned 3 cross in the lacing pattern it was for the whole wheel. But 3 cross on the disc and radial on the non disc side does make sense as far as the table goes. And completely missed that 28 spoke and 32 spoke. Must have had it in my mind the lefty was on right and JF was on left. I looked at the table 10+ times.
So in theory radial lacing on non disc side will save like 3g of weight in spoke length. And 3 cross will be slightly stronger? Would it be advised to go radial lacing since the max non drive tension is 60kgf, or is that just because it is radial laced and if I did 3 cross I could get away with 100kgf on both sides? I'm using a carbon rim so I'm wanting to tension the hub as high as it's rated, so 110 disc side and 70 on non disc side at the moment.
Really appreciate the help.