The developer of Flarum also created the esoTalk forum software. Demo can be found here
http://esotalk.org/forum. It just looks like old school forum software though, but with a more minimal and modern design. You can style SMF and produce something similar. Nothing revolutionary there. Discourse seems more innovative and at least attempts to create a new type of forum "experience".
I think what makes innovating with new forum software so challenging is all the people that got used to older software. Those old forum software all have a similar way of organizing information. Anything that tries to do something unique is met with an initial "WTF?" type response from people that spent a lot of time on software like SMF or vBulletin. New forum software for the most part seems to want to just behave exactly like the old stuff. FluxBB is one such software that I had high hopes for, but there hasn't been much innovation here either (demo
http://fluxbb.org/forums/index.php).
One of these persistent forum behaviors is how sections are presented. Forum software almost always presents all of the available forum sections to you once you join. Unless the site is very specific and niche, you won't care about most of these sections. I don't care about the local, altcoin, and trading sections on here. If you want to fix this, you are expected to poke around in settings. The software expects you to clean up the mess it created. An opt-in model would be a better experience. When users join they automatically opt-in (or "follow") the Meta and Bitcoin Discussion sections (+ their local section if detected that this is needed), but they can optionally follow more sections, or decide to temporarily have the entire forum be visible to find new sections to follow. There can be support for user created & moderated sections. Users can pay the forum a monthly fee or a one time payment for the privilege of having their own section to interact with their customers, or other bitcoiners that share similar hobbies. Such an arrangement seems very much in the spirit of decentralization.