Did you manage to get IPv6 prefix delegation working with dynamic prefixes? Best solution I found involves scripting to re-build config files and restart a daemon, where OpenWRT just does it out of the box.
Outside of Tokyo you can still easily get one of the other regional IC cards [1]. They can now all be used everywhere in Japan including the Tokyo subway, provided you don't start travel in one region and end it in another.
At my electronics engineering school we had access to everything we needed to mass-produce those decoders and did so at a reasonable scale to pay for our studies. That was a lifeline. Knowledge of TV signals gave me my first job, during which I got to work with the guy who designed the scrambling system and had a chance to thank him in person. Small world.
If I understood correctly, the link between ULA-based address and host name is done through a DUID. This is assuming that DUID values do not change over time and can easily be harvested from everything you want to connect to the local network. What guarantees that DUIDs are fixed and easily collectable? What are the solutions if they aren't?
Having a generic "Send to" would only solve a part of it though. There is currently no standard way of connecting the two ends of the same cable to two computers and expect them to exchange files without heavy configuration on both sides. Wireless goes the same way.
They even have a decimal clock dated from the French revolution: 10 hours per day, 100 minutes per hour, 100 seconds per minute. Total of 100k seconds/day, making seconds a bit shorter. Was largely ignored, only lasted a few years.
The computer section has a ZX81, a ZX Spectrum, an Oric Atmos, and a Commodore 64 on display if memory serves me right. All my childhood computers, feels weird seeing them in a museum. My kids were amazed by the first calculators made of paper and cardboard.