Refactor parsers for better readability

**Feature request**
It would be great to have backup for middleware.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_backup` with default `false`.

No file or test is named. Start by locating the parser, middleware, and existing configuration options, then trace how middleware is deployed and configured. Done means the `enable_backup` option defaults to `false` and the requested middleware backup behavior is covered by an appropriate test.

Written by the indexing model from the issue text.