Apart from the extra blocks, you can add the content to the email body. Please use those WooCommerce Deposits & Partial Payments shortcodes, which are listed in the Shortcodes section. Depending on the template you're editing, this section will display only the shortcodes that are available and compatible with that specific template.
WooCommerce Deposits & Partial Payments has one element for the partial payment detail here.
And don't forget to enable and save those templates.
