Allow empty migration prefix with --migration-prefix=""

Problem/Motivation

I'm migrating the Drupal 6 site with Ubercart and using Commerce Migrate Ubercart and DDEV.
Commerce Migrate Ubercart is looking for dependencies without a migration prefix "upgrade_", so I decided to use the command:

ddev drush migrate:upgrade --legacy-db-key=migrate --legacy-root=https://stage.example.com --configure-only --migration-prefix=""

But this generates nothing. At /admin/structure/migrate/manage/migrate_drupal_6/migrations
There are no migration entities yet.

Migration Dependencies
upgrade_d6_user, upgrade_d6_node_type, upgrade_d6_node_settings, upgrade_d6_filter_format, upgrade_uc6_store, upgrade_uc6_product_variation, uc6_store, uc6_product_variation
Soft Migration Dependencies
upgrade_d6_field_instance_widget_settings, upgrade_d6_field_formatter_settings, upgrade_d6_upload_field_instance, upgrade_d6_filter_format, upgrade_uc6_product_variation, uc6_product_variation

Steps to reproduce

Run migrate upgrade with empty migration-prefix:
drush migrate:upgrade --legacy-db-key=migrate --legacy-root=https://stage.example.com --configure-only --migration-prefix=""

Proposed resolution

By default, migrate:upgrade generates migrate groups with a prefix "upgrade_". With --migration-prefix="" it should skip the prefix, as far as I understand.