What worked for me was I installed and ran Thunderbird, then I quit and copied the Google Takeout .mbox file to ~/.thunderbird/xxxxxx.default-esr/Mail/Local Folders. When I re-launched Thunderbird, it took a few minutes and then all my Google Takeout emails were browsable/searchable under Local Folders.

Also, I think there was a weird step involved, like I needed Thunderbird to connect to some email account, any email account, in order to get past the welcome screen.

It’s five additional accounts. Doesn’t matter their actual relation or location.

then put the baby to sleep

For a second there, I thought Steam had implemented a weird new CAPTCHA.

Reminds me of the guy who got his home raided and electronics seized for running a Tor exit node.

https://www.zdnet.com/article/austrian-man-raided-for-operating-tor-exit-node/

Seems risky and a huge legal hassle even if you don’t end up in prison.