https://fivetran.com/docs/databases/postgresql#limitations

Teleport Sync supports constrained varchar primary keys but not the Postgres Text data type for primary keys. Postgres community widely suggests the use of Text over varchar(n) and even defaults varchar() to the Text data type since there is no performance gain. Many ORM tools for programming languages now save a GUID primary key as Text in Postgres and require non-standard overrides to force it to a constrained varchar(36). ETL should be able to support these and your other diff sync methods support them. I don't believe you need to support all DB Text types since most are not performant, but the Postgres Text type is different and is widely used by the community.