I am pleased that you are looking into what the government is doing to help Rolls Royce building the first SMR. If you want to create a new industry, government subsidies are a must.
I can't understand why we haven't been doing that stuff for the last fifteen or twenty years.
Same with housing. If you build in factories you have a controlled environment and can build far faster and more accurately, using modular construction. Everything is repeatable and controlled.
Edit:
In terms of small reactors, you could place them near large demand centres and supply baseload power. This would maybe lessen the need for grid reconstruction and new power lines. Security may be an issue - since they are nuclear.
One issue in relation to complimenting renewable power sources is that traditional nuclear, like coal, needs to be kept hot and on stream, or you get severe penalties from cycling hot and cold. The old coal stations were badly impacted by that, necessitating much earlier major refurbishment than if they were kept working at high capacity. I don;t know how SMR technology copes with heat stresses. They might not be suitable to come on and turn off as rapidly as combined cycle gas turbines which don;t care about that, and can come on stream rapidly when demand peaks of when renewables drop off the grid.