Balance due after order edit.

Hi All.
I need to find (or build) a way to save the balance due after an order has been edited through admin (removed products, added products, changed shipping, etc). So I can show in the order details if there is a payment or refund to be requested/done after the changes are made. Does Opencart save this information somewhere? (I can't find where) If not, that's ok, I will probably need to write a new module and a mod for this, but just want to be sure before I start coding.
Version: 3.0.2.0

Thanks.

As a new forum user, please follow the forum rules. No OC version posted. However, the balance can be seen in the admin customers page once the total being confirmed when an order either gets added or edited from the admin based on the order total extension module you might be using.

Sorry.
The Opencart Version is 3.0.2.0.
I know you can check it after edition. I was wondering if you can check this value before hitting the save button.

Another question, let's say you added a product to the order, and you end up with a balance of $30, then you have to edit again to change the shipping method because you forgot to change it in the first edit. After you save again the balance becomes a $0 refund. And you lose the old balance value.
Is this behavior ok? Or is something wrong?

I think it should keep the balance due until I check somewhere else that the pending amount has been paid. And I should be able to edit the order as much as I want in the meantime.

Thanks.

I know you can check it after edition. I was wondering if you can check this value before hitting the save button.

Yes, this is what the Opencart API is about as explained on the above.

Another question, let's say you added a product to the order, and you end up with a balance of $30, then you have to edit again to change the shipping method because you forgot to change it in the first edit. After you save again the balance becomes a $0 refund. And you lose the old balance value.
Is this behavior ok? Or is something wrong?

Opencart out-of-the-box does not use balance with shipping extension modules. The issue you are experiencing must be originating from an installed extension downloaded either from the Marketplace or from a 3rd party website.