I took a career aptitude test and it told me I should have been a software engineer and idk if that has anything to do with this, but...
Tl;dr: I got high and there's got to be a way to do it in this here vote-time continuum!
On a superficial level, couldn't you get creative with lemmy community settings (using a new sister community) and create only pinned posts/threads (may be subject to mod approval) which are then autosorted by new comments using some scripty pinned post reordering logic? That probably could only apply to a single community though...
The extent of my web design knowledge is limited to fuckin around with myspace html buuut, with more lemmy UI settings, could users elect that certain posts are "forum" worthy? As in, "this is a meme teehee" or "this is a topic worthy of revisiting over a greater period of time" kind of thing. And barring any weird astroturfing, these posts get "pinned" to be revived at the top of the community whenever some reply or top level comment threshold is passed. Inversely, pinned posts could fall away into an archived state after a certain period of no activity, much like the rest of lemmy that's over a week old (whether it's actually no longer active or not).
Getting pinned (hehe) would probably require meeting various straightforward thresholds (like relative or absolute vote value and/or the ratio of upvotes to "pins"). That could determine a sep for how long a post/thread remains subject to revival by reply.
If this configuration were applied to lemmy in general, I think to encourage participation, I'd say it should be an opt-out situation when visiting a specific community (do you want to see community-pinned posts?) and an opt-in situation when choosing to include "active archives" content in a homepage feed.
Not really sure about implementation, but to me it just becomes a secondary voting system as a means to value longevity of a topic, and various ways of incorporating those data into user sorts, community pages, and news feeds that might want to utilize.
Simple as that, right?
^heh^