Author here.

You are right, the main downside of the approach in the article is that you have to remember to filter the deleted_at column on constraints and consider how foreign keys cascade.

About triggers, we do link at the bottom to an article that uses them: https://brandur.org/fragments/deleted-record-insert

Since I am exploring a sync engine, having a separate table for deletes means I’d need to run additional queries when catching up, which led me to explore the single table approach. Let’s see how it evolves.