"Techno-conservatism" isn't a political stance. Ecological harmony isn't a political goal, it's a prerequisite of any durable regime at all. The thing is living in harmony with nature is fun and economical so I would hope it's very popular once you've experienced it. (E.g. we have some hydrogen-powered buses here and the exhaust they put out is not smelly poison, it's actually refreshing! It has a delightful not-quite-aroma, it's moist and oxygenated. You only have to stand upwind of one once to realize that ICE vehicles are inferior.)
In the short-term, and on the personal scale, I'm imagining something like a neighborhood or small town as a kind of experimental zone or context. ( Check out Village Homes https://en.wikipedia.org/wiki/Village_Homes ) You're right that this wouldn't mitigate truly global issues like "forever chemicals" or global warming, but it's an improvement on what we're doing now. I think once there's a kind of "theme park" you can visit that shows what it's like to live well without messing up the environment it would really convince people to do it.