Does scaling up mean making a bigger setup with magnets of the same strength? If so, I agree it is just a matter of making the effort, but this 150-ish MW thing is "half the size of ITER", which means it already is enormous (ITER will be gargantuan with its 1400 cubic meter vacuum vessel).
Even at 'to the fourth power', I fear this would get really huge before it significantly improves on our largest fission reactors.
Alternatively, can one inject more fusion material while keeping the same magnetic field strength to get more power out without building a larger device, or would that require stronger magnetic fields? If so, are we sure we can make those stronger fields? (Correction welcome, but I don't expect we can; if we could, we likely could scale this design down)
I still think that, if this works as advertised, it will be both a huge result and only one important step on a long road ahead to 'free' clean energy.
The first nuclear power plant attached to a grid was only 6MW. The first "full-scale" plant, according to Wikipedia and the BBC, had four reactors producing only 60MW each.