> This news shows that practical fusion is now only an engineering problem, not a fundamental physics one - like it still is for Tokamaks and Stellarotors. For them no one knows if it is even possible to e.g. control turbulence long enough to achieve net positive energy gain.

Well, sort of. This is "theoretical breakeven" - the reaction generated more energy than they put in. "Technical breakeven", where you generate enough power to run the thing, is 2-3 orders of magnitude away. It's not at all clear that pulsed fusion like this is a viable power source even if it reaches technical breakeven.

The magnetic containment people are still struggling, but making progress. For a long time, everybody was looking for some clever magnet geometry that would yield stable plasmas, with limited success. Maybe active control will work. There are now people throwing machine learning at the problem.[1]

[1] https://news.mit.edu/2022/fusion-machine-learning-turbulence...