Consider this a configurable option. That the organization can turn on the option and configure if it wants to allow invoice editing and the defined time for editing (think of easy options such as 1 day, 1 week, 15 days, 1 month, 3 months... etc.

Also consider canceling invoices with permissions from POS and Backoffice. As well as the option of being able to return the products on the invoice to the inventory or not.

this should include removing and adding products. Always asking the reason for deleting and whether or not it affects inventory.