I think this project would really benefit from taking one of the excellent existing voice assistant/speakers on the market (Google home, echo dots, etc., and flashing them with some custom firmware.
Arguably, being offline and keeping your recordings off the cloud, it is already superior to commercially available options.
I've just looked over the docs. I'll probably be playing with this very soon.
If the primary issue is the same as me, that you download too much crap without paying attention to available storage, just use the terminal emulator to create a 25-100mb file you can delete when necessary.
[1] storage ️ internal ️ apps [2] If you use PWAs to cache data and avoid high data bills, keep in mind that clearing browser cache clears PWA cache as well (my most-used PWAs are for hn and xkcd)
Would love to have great hardware for custom tinkering though. With more development time and money behind this project, I hope it could grow into a great tool.