If Gemini 3 flash is really confirmed close to Opus 4.5 at coding and a similarly capable model is open weights, I want to buy a box with an usb cable that has that thing loaded, because today that’s enough to run out of engineering work for a small team.

Open weights doesn't mean you can necessarily run it on a (small) box.

If Google released their weights today, it would technically be open weight; but I doubt you'd have an easy time running the whole Gemini system outside of Google's datacentres.