>1. Hardly anyone knows about it
to my understanding, that's the reason list is being made ^^;

>2. Not n00b-friendly to install and configure (compared to others)
I disagree, it only requires surface level familiarity with cli to install. PHP itself is easy to install (compared to nodejs). It loses installment easiness to vichan because requires a non-web accessible backend... but this is intended for certain flexibility (eg having boards on img.heyuri and dis.heyuri being connected to same "main part").
I'd say configuring is the same level of hardness, though kokonotsuba requires careful updating that admins would want to check https://github.com/Heyuri/kokonotsuba/commits/main/global themselves to see changes made to "global/" folder. The way configurations work is being modified right now, so this may be immediate subject to change though

>3. Not 4chan/8chan-in-a-box - it misses many features, bells, and whistles that are expected on those types of systems, and that's what most new imageboard admins want
it doesn't have features of 8chan (user curated boards), maybe that's something to note.. I eventually want koko to have OPs being able to moderate their threads, for similar effect of smaller scale

>4. No proper release structure or easy upgrade method
It's currently a rolling release software to save us from additional work of documenting releases.
I'll admit upgrading it isn't very easy (aforementioned cli/reading code requirement), but I'd debate if other alternatives are very easy either