I'm not just building these circuits to just drive 7-seg displays. My blog series is building up the knowledge, code, and circuitry to be able to drive arrays of 8x8 LED matrices and into double-digit-n nxnxn LED cubes. This blog post was about how to daisy-chain shift registers, not about the most compact, code-tight way to drive 2 x 7-seg displays.
I completely understand what you're saying - but for pure 7-seg display driving, you're doing it a different way from me - extra h/w vs. extra code. There's no saying one way is better than the other - the solutions have different characteristics.
So there's no point arguing about it.
Thanks