Yes, triggers and stored procedures are supported. Concurrency is the only real limitation in terms of functionality.
The bundled in-memory database implementation is mostly for use in testing, for people who run against mysql in prod and want a fast compatible go library to test against.
For a production-ready database that uses this engine, see Dolt:
> No transaction support. Statements like START TRANSACTION, ROLLBACK, and COMMIT are no-ops.
> Non-performant index implementation. Indexed lookups and joins perform full table scans on the underlying tables.
I actually wonder if they support triggers, stored procedures etc.