measure the impact of database changes before you merge.
When database schemas change, code has to catch up. Too much of that code is out of sight and out of mind -- in other modules, other systems, other repositories -- and gets left behind. After migration that code still expects the old structure and breaks. Chaos ensues.
Migration scanning at launch covers SQL scripts only. ectomigo is tested against PostgreSQL, but the relevant differences between that and other SQL dialects are mostly minor.