JCS doesn't work worth a damn. It can't work, there's too much code controlling the maze, swapping data without modifying code causes problems. Even though published mazes 2 and 3 have nearly identical programs (here on atarimania), and the mazes themselves are similar, #3 received 2 small code patches totalling only about 50 bytes which keeps the game working. One patch is for counting the Cheerios or Fruit Loops eaten to know when the level is complete, the 2nd patch controls movement of baddies while they're only a pair of eyeballs after being eaten. One extreme is the eyeballs dive straight for their home box then come back at you fast, gameplay relies on the eyeballs wandering around a little on their way to the box. The other extreme is they wander eternally without entering home box. Changing maze walls without patching code ruins this effect. More daring mazes create other troubles.
Whoever wrote to the disk while tinkering got tired of this fast. The game file "JAW.GAM" is executable and modifies the original (90 degree) by removing a pair of Cheerios, tiniest little change saved back to disk, And the boards can't be completed in play because the token count is a mismatch.