Well, I'm thinking that it's similar to how the cache for mac computers is stored on the ram. Everything runs smoother because you can easily pull processes without having to do a full boot, but after awhile, the cache will fill and the thing that was supposed to make everything faster ended up slowing things down.I really don't understand why Xycraft would 'cause' chunkloading. This decision should be up to the player, not the modmakes.
That explains.
Portals keep chunks loaded because it's easier to move into a loaded chunk, it makes sense. Until you have too many loaded chunks, and you find it hard to move at all.