The reason why the sea graphics aren't mentioned, is that they are of exactly the same size as the original ones. It causes no extra work for the computer and reverting to the old graphics is a purely aesthetical choice.
As for a real resource hog, the EB script sucks up a lot of your juice. We prefer to cram stuff into it, however there are a couple of variants concerning the client rulers that run faster than the default 1.1 script.
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