Skabob, if you want to avoid wasting vinyl, then stop dyeing discs. Realistically speaking, if you have a 30" plotter you can waste *less* vinyl.
30" vinyl is actually 28.5" (in cahoots with those 2x4 assholes, no doubt) but if you plan your job to cut the vinyl in squares measuring 9.5"x9.5", you can get three discs worth of vinyl out of one 9.5" strip. It doesn't leave room for error, and with larger diameter mids it barely covers them, but I haven't had any problems and I've been hand-cutting my 30" roll this way from day one.
For even less vinyl wasting, look for a different way to apply the dye. If you can paint the dye on as a viscous liquid that will stay put it removes the necessity for the "vinyl boat" in which the disc braves the RIT ocean. You can mask off just a small area for a small design, like 3"x3" total, without wasting an entire 9.5x9.5 piece.
Jubuttib, your assumption that factory dyes don't bleed over time is erroneous. They bleed just as much as any other dye. It's easier to notice on an crazy intricate dye from AcidBath than on a splatter flydye. When a splatter dye bleeds through the plastic it just becomes a slightly more spread-out splatter and still looks like it was meant to be that way. When a dye of the Incredible Hulk bleeds, the fault is easier to spot by a few orders of magnitude because the Hulk ain't supposed to be blurry and the eye notices with little difficulty.
We are not like those other golfers. We throw our clubs and keep our balls where they belong. -Ol' Bob