We are talking about an application file format, so "type errors" are about who's right: the application (even better, multiple equally right implementation of a specification) or random hackers altering the file in incorrect ways.
Loose type checks, e.g. NOT NULL columns of "usually" text, are loose only compared to typical SQL table definitions; compared to the leap forward of using abstract tables and changing them with abstract SQL instead of using text or byte buffers and making arbitrary changes, enforcing data types on columns would be only a marginal improvement.
Loose type checks, e.g. NOT NULL columns of "usually" text, are loose only compared to typical SQL table definitions; compared to the leap forward of using abstract tables and changing them with abstract SQL instead of using text or byte buffers and making arbitrary changes, enforcing data types on columns would be only a marginal improvement.