I ran a server with low ram using FTB and Mystcraft was causing a big problem.
- Turn off world corruption via server config.
- Limit age creation to only admins or people who know how to create stable-ish ages even with corruption off.
- Make a central nexus where everyone has their own 'hub' with a portal to their bases and extra worlds.
- If you're going to allow people to make their own ages, spawn in a creative mode notebook and linkbook modifier.
- Whenever creating an age a player should have to label the age via it's id, just in case someone got stuck in an age, the world gets way too laggy, or any other problems show up, an admin can use the tpx command or the dimension can easily be deleted in the server folder.
- Create a centralized mining age with dense ores and acceleration where everyone could build quarries and community farms.
- Give each age a world anchor right under the spawn so it would keep the chunks loaded. That will remove chunk loading lag when a player enters it as long as the world has been loaded once.