Any reason why you decided against Discourse? To me, it seems like the more modern forum, or at least with a better UX... Except that it's Ruby+Postgres instead of NodeJS+Mongo, of course 😉
Yes, mostly due to personal experience (I had used NodeBB but not Discourse as much) AND as you stated, the tech stack... I'm not that familiar with Ruby compared to Node and JavaScript, and as I'm the sole maintainer of the site and I do this in my spare time, that plays a significant role.