User blog comment:MachineGunSuper/Question/@comment-32213734-20180225032808/@comment-30754445-20180226202729

Take a look at this table. Psi Levels beyond 1000 are meaningless, because Level 1000 is set at infinity. The whole point of this scale is to cram the entire realm of positive numbers to the interval (0,1000).

Moreover, there are pretty big gaps in the scale that correspond to the current limit of human knowledge. The mid 400's, for example, is reserved for computable functions that do their recursion far more efficiently than anything currently known. Similarly, the 800-1000 range is reserved for numbers that cannot be described with our current concepts.

(There are also smaller gaps as well. Starting with the 260-300 range things begin to get untractable very quickly)