I populated the first V3.0 PCB today. It's actually been through a few iterations, but I didn't even bother filling any of the earlier boards. This one is finally worth building. The board is smaller now (23mm diameter), so it fits inside cheap, widely available "5g" polystyrene jars, but still uses an inexpensive replaceable CR2032 for power.
This first PCB uses an OSLON Signal Verde LED. I tuned this particular PCB to a 2-year run-time (12.5 uA) on a CR2032, and it blinks at 157 Hz. The breadboarded version needed to be tuned to 123Hz to achieve the same run time (probably due to the 30% inductor tolerance). The ability to fine-tune the current draw was one of the design goals of the V3 (as was fitting inside these jars).
I also have PCBs for Luxeon C and Cree XPE / Cree XPE2 LEDs. They are identical to this one except for the LED pads.
Here's a visual comparison with the previous two generations for reference:
One of the key differences is the use of a through-hole CR2032 holder, which is actually smaller in diameter than the surface-mount version (since the through hole doesn't need flat mounting tabs). This was the final change required to fit the PCB inside the jar.
Tuned to the same 2-year run time as the V2.0, the V3.0 is noticeably brighter. It's roughly as bright as the V1.0 (which only runs 1 year). But, you can tune the V3.0's brightness to last from less than 1 to more than 10 years on a CR2032 cell.
I'll put together a more detailed post for those wanting to build some of this new version, including a BOM and placement diagram. The PCB designs are already in GitHub, I just need to polish the software a little and put it up there.
EDIT: I discovered that the clear jar makes a nice dim ring of light when placed upside down. I usually keep a few of these lights on my nightstand, but the light can actually be enough to bother me. Being able to attenuate the output somewhat by turning them upside down is an added bonus, especially since it looks so cool.