IMHO "no set tillering" is just a catchphrase to remind ourselves that we should never overstress the stave while tillering. At least never pull on it more than your intended draw weight. I would add never pull on it while too damp, while there is a hinge developing, while too hot after heat treating, etc. This is probably why some experienced native American bowyers never even string up a bow while tillering.
I floor tiller and string up the stave and just use the curvature for tillering. I do pull on the bow a dozen times or so after scraping, but usually for much less than my intended draw weight. I use rather short arrows to shoot it for the wood removal to show up.
As for the shorter limbs, the easiest way to think about it is to see if the longer limbs are not fast enough by cutting the tips a little and scrape the limbs a little to make the draw weight same. If no set is induced in the process, the "shorter limbs" must be faster because we just made them lighter.
Come to think of it, shorter limbs of same draw weight is always lighter than the longer limbs, so long as no set is induced in making them shorter.
