For example, a target selector with a large coordinate range such as @a[-384000,-256,128000,dx=768000,dy=512,dz=768000] will lag excessively.

I assume that in the code, there is a long loop that cycles through every single possible coordinate in that range, and detects if there's a player there. This system causes a TON of lag, and that's definitely not what it should do! (Even if that's not what it does, what it does seems to be really laggy anyways.) The less-laggy way to calculate players in that coordinate range is to just detect to see if their coordinates are <= the positive corner of the specified box selection, and are also >= the negative corner of the specified box selection. And I'm sure the math to figure out what the coordinates of the two corners are couldn't be that difficult.

This bug is causing me to disable a command block that prevents an extremely exploitable action from taking place. With this bug existing, there is a huge security problem on my server. Please fix it! Whenever I enable the command block, the server times out and crashes due to the extreme lag.