I like the feel of solarpunk a lot, and it slots well into fantasy. Something I think you might consider in the setting, especially with the focus on relics, is how the past was overall a rather destructive one, like technology/capitalism gone amok, and how the current society is still struggling occasionally with the consequences of the past. A lot of hooks can be mined from that!
You mention that Community Trends are primarily not “species” but Constructs don’t seem to quite fit that idea. I might recommend that instead maybe that third category could be inclusive both of these constructs but also people who are interested in recycling old technology. Not necessarily trying to resurrect the old world, but use what is still good, as I think that fits the solarpunk ethos really well.