It still seems worth pursuing the 'Romantic' typology of Lowy and Sayre, for a variety of reasons.
One admirable aspect of their approach is that, after identifying various tendencies that they construe as 'Romantic', they identify these tendencies in various statements and works produced by individuals who themselves may have held different, even opposing views at other points in their lives. That is: they don't simply assign authors and works to a simplistic overarching category. They see the ways in which the underlying ideas can be expressed partially.
One key aspect of their definition of Romanticism is that it looks to the past when critiquing the present. But they distinguish between folks who want to simply return to the past, and those who rather use elements from the past to inform utopian visions for the future -- visions which may also contain new, even futuristic elements.
There's a certain reading of their expansive definition that makes Romanticism seem almost trivially correct: if we are to come up with a critique of current practice and life-world and how humans fit into it, what else would we do but to look at other examples (present and past) of human societies from which to derive inspiration and perspective?
Perhaps even this broad and shallow intepretation isn't so trivial as it seems at first, however, because the ubiquitousness 'modernism' and the assumption of 'linear historical progress' is such a strong, underlying prejudice in most imaginings of the future. The idea seems almost always to be to look at the last decade or two and extrapolate to the future in a 'science fiction' mode.
In largest part because it is a critical lens on industrial modernity that is somewhat outside the usual anarchist / communist / socialist spectrum / landscape. Importantly: it's not that it's completely outside -- some Romantic authors (e.g. Kropotkin, Morris) share much in common with anarchist and socialist standpoints. But generally, socialists tend to imagine using the same industrial machinery as Capitalism, but 'owned by the workers' (in some relatively diffuse way), typically overseen by the State. Anarchists eschew the State, but often in ways that are deeply enmeshed in Enlightenment concepts of the individual and the community; anarchists often seem to speak as if they've discovered a new, truer mode of humanity that focuses on individual freedom is unfettered by any old-fashioned, historical practices around how people relate with one another (though I suppose the German Romantic focus on the Self isn't so different in this regard). 'Traditional' social structures -- families, say -- are eschewed in favor of novel reconfigurations.
In contrast, the Romantic perspect looks to well-established modes of human relationship from history in order to critique the present. It tends to focus on a given place or culture's relatively recent and local historical practices, as they are best known, and most plausibly implemented.
In spirit, it's akin to someone in New England saying: looks like the global supply chain is shaky. Yet, people in this very town were able to feed themselves from food grown within 100 miles, less than 100 years ago. Would it be possible to re-implement some of those systems sometime in the future?
Review in New Left Review: https://newleftreview.org/issues/ii138/articles/harriet-friedmann-farming-futures
What are the key elements?
Appropriate tech. Analog tech. What can be manufactured locally. Of that which can't: what can be manufactured in a way that would last. Starting a design / workshop series on this idea.