Note the 4s alternate sides. Multiplexing occurs when more than one ball is in a hand at a time. Then, with multiple balls being thrown during any given beat, the throw heights are given for each of the throws made. The convention is for square brackets to denote the different throws made by each hand. They both deplete the pattern, and then suddenly give it all back in a burst of balls.
Computer programs exist to furnish valid tricks under any scheme of rules.
Siteswaps make up a doubly-infinite family of tricks. Already, there are an infinite number of balls one could juggle. Then, at each number level, if the throw height is unbounded, the number of different tricks is unbounded. The richness grows like the factorial of the throw height, and like the factorial of the number of balls. There will always be uncharted territory in the humanly accessible land of siteswaps.