Just make sure you use two good-condition copper washers per attachment (one on either side of the banjo fitting). As long as you do that, you could have 14 separate brake lines and they won't leak.
I'm not entirely sure what the junction block on the forks is for. My initial thought was that they used it to split the brake pressure between an optional dual-disc front brake on certain trims, but to my knowledge they never offered a 440 with a dual-disc front option. Perhaps they use the same brake lines as on the KZ550 LTD which may have had a dual-disc front available. It could also be there to reduce friction and simplify safe mounting of the brake line through the triple clamp area, providing a rigid attachment point for securing the brake line to the frame. Regardless of the actual reason, I trust Kawasaki's engineers knew what they were doing and probably had a reason for the split, so it's probably best to leave it present.