In the very old days when RAM was limited, floppies were the only way to get stuff out of your computer and gradients hadn't been invented (must've been Illy3-ish when you still couldn't draw with the preview turned on), we used to make blends out of single strokes instead of boxes.

Use reasonably thick strokes and a fairly large number of steps so that you don't get visible gaps. This gave (and still gives) very smooth and light (in Ks) blends. And (once you've expanded them, which you didn't have to back then) they're easy to edit because you can select single lines more easily that rectangles with the preview turned off. You can also of course select batches of strokes and re-colour them with the blend front to back filter.

Which all goes to show that:
A) I'm an antique
B) Some of the old tricks are quite as good as the new ones and you won't find them in the handbook.
:-)