New features:

Complete and full spawning system remake that allows the ability to change all spawner requirements and conditions.
Added new options for nearby entity limit, holograms, changing, owned spawners, entities and more.
Added spawner warnings that shows if and why a spawner cannot spawn any entities.
Enhanced shop and upgrade GUI layout customization.

New commands:

/sm location [view/validate/clear] - to view, validate (remove invalid or duplicates) or clear spawner for a specific player.

Fixes:

Fixed items in spawner view having visual errors.
Fixed slime option not working correctly.
Fixed entities spawning in blocks.
Fixed other minor bugs.

API changes:

Large spawner API part has been changed, so any that is extending SpawnerMeta will have to add support for the new API version.