Thanks to everyone for the feedback so far! I do appreciate it. (And good Karma to you all!)
Decoupling Capacitors: Know about 'em, but this thing has no processor and the oscillator runs at under 100Hz. In this case, according to what I've read, they're not needed.(?) But that does bring up an interesting question: The power supply will be a good distance away and this will be powered via a long wire. So I was thinking of adding a, say, 10uf or so capacitor across VCC and GND to smooth out any noise or interference on the power line.(?)
VCC connected to VDD: because in the Eagle parts libraries, it is not consistent how parts get power. Some use VCC, Some use VDD, and some use GND and some use VEE or VSS. Slowly, I am building my own personal parts library and correcting some of these inconsistencies.
Ground (Power) Planes: There are actually 3. VCC, GND, and the LED common along the right edge. Total current draw is only about 30ma, so big planes certainly are not needed for power. But at the low frequency, neither is a RF ground shield. Having the VCC plane on the left side and the LED Common plane along the right edge simplified the layout and made it cleaner.
Mounting holes: Not needed for the current project, but good suggestion! I think I will add them. I'm gonna end up with 40 of these boards even though I only need 5. The rest may get repurposed so the holes might come in handy later.
MAX6971: Great chip, love it! But VERY EXPENSIVE (even the Chinese counterfeits) and would require more sophisticated and expensive circuitry to feed it. Also, only 1 output needed at a time.
SMD: As discussed in the design notes, I considered it, and for the reasons given in the notes decided that DIP and thru-hole was a better option for this particular project. May reconsider it in the future.
Keep the feedback coming! And if someone can explain why I truly need the decoupling caps on this low-frequency, no-processor circuit, or if I should add a power cap, I'm listening.