The challenge that isn't covered here is that the grandeur of Singapore is far far easier to achieve with authoritarian centralization than the anarchic style of solarpunk. And people are compelled by the grandeur of a large expensive project in different ways than the DIY scale.

So how can a ragtag group in SF or Berlin make something that captures imagination just as well as Singapore?

Recently had a talk with a pragmatic ecologist who was talking about the need of "counter-tales". As I understand it, the idea is to not directly contradict a take on a movement (we were talking ecology in general but it applies to solarpunk) but rather give the appearance of participating in the take will subverting it with your own elements. To take Singapore's example, if you were to take inspiration from their style but to create an actually positive society in such a setting, and have a bit of success, fans of your work would go from "Oh, Singapore system's create really nice solarpunk settings" to "Ah, Singapore is pretty but it misses the point of this esthetics"

Also, illustrators must also understand a bit architecture and urban planning, and why it matters. Some architecture will be inherently authoritarians. Favoring good external looks over practicality for inhabitants hints at a coercive urban planning.

Also, and I leave that in the end because it may be an unpopular opinion, but I think in that fight, generative AI can help to visualize ideas, to convey what writers are imagining. If you write a text about an utopia, it is now cheap to illustrate it to give an idea of what is in your mind.