There is research showing that adding lanes only helps for maybe six months. Then people realize that the route is better and change the routes they take, which leads to more congestion again. Fewer lanes can actually decrease congestion.

https://smv.org/learn/blog/how-does-roadway-expansion-cause-more-traffic/

Darmok and Jalad at Tanagra

I think your server will only download content if one of your users views/subscribes to it, so maybe you could disable signups so that you’re the only user on your server? This would still allow users on other servers to subscribe to your communities.