Custom Email Header

-- HikaShop version -- : 4.7
-- Joomla version -- : 4.2.3
-- PHP version -- : 8.1.11

I commonly include a custom email header in emails sent via Joomla's Mail class (e.g.: "x-customname: sample;", which are added by using PhpMailer's ->AddCustomHeader method on Joomla's Mail class, which extends PhpMailer). I'd like to include a similar header in Hikashop's generated emails, mostly to help me use rules to sort my incoming mail, but partly to do things like identifying which of HikaShop's templates was used or including custom data from custom plugins I occasionally write.

I know I could modify HikaShop's mail object, but is there some kind of override method or plugin process that wouldn't be overridden by updates?

Could you add this as a possible feature to include in a future update?

Thanks. I didn't know if the $data value provided to the plugin was an actual Mail object or just a structure holding the requisite data.