What you are doing?

Sequelize has a parameter in it's constructor called options https://sequelize.org/api/v6/class/src/sequelize.js~sequelize#instance-constructor-constructor
which has an item called define (more on the define) where additional items such as underscored, paranoid, timestamps etc. can be specified.

In my custom config file specified in the .sequelizerc, I have the that options object, however, they are not being picked up.
It seems like only the underscored work if and only if included in the model:generate as an option --underscored

// .sequelizerc
module.exports = {
  'config': path.resolve('src', 'myconfig.js'),
  'models-path': path.resolve('src', 'models')
};

// myconfig.js

const username = process.env.DATABASE_USERNAME;
const password = process.env.DATABASE_PASSWORD;
const database = process.env.DATABASE_NAME;
const host = process.env.DATABASE_HOST;
const dialect = 'postgres';
const options = {
  define: {
    underscored: true,
    paranoid: true,
  },
};

module.exports = { username, password, database, host, dialect, options };

// Also tried this:
const define = {
  underscored: true,
  paranoid: true
};

module.exports = { username, password, database, host, dialect, define };

What do you expect to happen?

I expect the config attributes to be picked up and work such that the migration file would include a deleted_at and the createdAt and updatedAt would be created_at and updated_at respectively.

What is actually happening?

It's not picking them up and using the default behaviour. It works exactly the same way with and without the options.
The deleted_at is not created. The createdAt and updatedAt remain the same.

Dialect: postgres
Sequelize CLI version: 6.4.1
Sequelize version: 6.21.3

Edit 1:

include the module.exports in the myconfig.js as per the comment: #1139 (comment)