That’s not an issue. We know we need separate tax codes for outward and inward. I’ll figure out so the presentation is right on invoices and the words “outward / inward” or whatever you choose will not leak into printed invoices.
Also, I know we end up with many tax codes but I will probably implement some mechanism where you can specify transaction form types where these tax codes should be applicable so they are not a choice everywhere. This will make things simpler for user so they won’t see inward tax codes on sales invoices as an example.