The decisive thing is always going to be cost. Thus far, reducing capacity has made nuclear plants faster to build, but the outcome was more expensive per MWh [1]. This then forced future plants to again increase in scale, but it again made them too slow and expensive to build, with huge budget overruns. We're now back to small modular, but if the electricity they produce is again even more expensive, it will offset any other benefit.

[1] https://www.researchgate.net/publication/275673955_The_forgo...