invoice/packing slip: orders products and payment only available in one language

[gernot]

ZC 1.5.6c
PHP 7.3.8
MariaDB 10.3.18

Plugins:
multi-language country names v1.1.0
multi-language zone names v1.0.0
sitemap XML 3.9.6
Easy Populate v4.0
Image Handle 5 v5.1.5
Stripe v1.3.4
Direct Bank Deposit v1.5.3
Skinny About Us Page v1.0
CKEditor v3.7s
Structured Data Plugin (master from git)
Google ReCaptcha 2 v3.4
Flexible Footer Menu Multilingual v1.5
Gift Wrap Module v2.14
Edit invoice & packing slips v1.0.2

Hi, I use English and Japanese on my installation, and noticed that while I can display invoice and packing slip in either language, the order product information (stored in table orders_products), payment method and shipping method (stored in table orders) are only in the language in which the order was originally placed.

Result is that parts of the invoice and packing slip remain in only one language, while other parts are translated depending on the language chosen for the display in the admin screen.

I did not find any modules to make order information multi-language capable, and expect that I can do this myself with two extra tables and some modifications to the queries in the order, invoice and packing slip code. But I am wondering whether this is not a large problem for any sites that use more than one language, and what people have generally done about it.

[gernot]

I note that for invoice, this issue also includes the titles of the totals below the products (from table orders_total), which outputs are created by the classes ot_subtotal, ot_shipping, ot_tax and ot_total.

[gernot]

Interestingly, totally different matter, but it looks like the order status is never updated in the invoice and packing slip, although the various changes in order status (updated in admin screen) shows up perfectly in My Account for each order.