Custom Email Triggers

This plugin claims to support custom email triggers, but when I look at the custom emails tab for a product, the only triggers listed are ‘on hold’, ‘processing’, and ‘completed’. The documentation says: Custom order statuses are automatically added to the plugin’s triggers list. Where is this triggers list managed? Is there a settings page somewhere that allows these triggers to be added and removed from the list that appears on the product ‘custom emails’ tab?

We have the Woocommerce Deposits plugin installed, with uses ‘partial-payment’ as a custom order status. How can we trigger a custom email of this status?