Customer portal and emails: show the charged currency, not the USD equivalent

Request

For a subscription priced and charged in a non-USD currency, the customer portal and lifecycle emails display the USD equivalent held on the subscription record rather than the amount the customer is actually charged.

A merchant selling a ₹199/month plan reports their customers see "$2.08 USD" in the cancellation email and the customer portal. Indian customers reading that reasonably conclude they were charged the wrong amount.

Current behaviour

Non-USD subscriptions are managed and settled in USD internally, so currency and recurring_pre_tax_amount on the subscription hold the USD equivalent. The portal and emails render those fields directly. The customer is charged correctly in the original currency, but nothing customer-facing reflects that.

There is no setting to change this.

Asked for

Display the customer-facing amount in the currency the customer is actually billed in, across the customer portal and all subscription lifecycle emails.