Wow, this is cool. I don't understand the bottom bracket attachment part. The photo shows the crank arm completely off -- which would take a lot more than 20 seconds! but the video doesn't.
It looks like a mount is attached to the bottom bracket,
perhaps by a bike shop if the owner is inexperienced
with that sort of work, then the cargo bike can easily be attached to
and detached from the mount.
There are more videos, one of which explains the bottom bracket topic, but note they are from 2016, see:
Initial mounting and setup will be a couple of hours, they talk about the time it takes to convert the bike back-and-forth once all setup and mounting are done.
This is a bit deceptive but that does not diminish that it is a good product, please note my comment in the other thread about connecting the Argo to Aluminum bikes.
Backed Kickstarter for the Argo and the delivered product exceeded all expectations.
I hope they catch on, the Argo is 1/3 the price of the fancy euro cargo bikes.