These are the currently available options in the config, however while there is an option to disable the spawner, or disable the speed, there's no option regarding the actual value of said speed or range.
If I've understood you correctly, you are looking to change the numeric values for speed, count or range? However I've purposely made it not possible to configure these values right now.
"disable_count": 0, "disable_egg_removal_from_spawner": 1, "disable_range": 0, "disable_silk_touch": 0, "disable_spawner_config": 0, "disable_speed": 0, "limited_spawns_amount": 32, "limited_spawns_enabled": 0, "monster_egg_drop_chance": 0, "monster_egg_only_drop_when_killed_by_player": 0, "disable_specific_egg_drops": {
These are the currently available options in the config, however while there is an option to disable the spawner, or disable the speed, there's no option regarding the actual value of said speed or range.