Wasn't sure if you wanted this in a separate thread or not.
4.22
Major Issue
Order Details on Submit Order (before submit) and Order Summary (after submit) do not show variants. Attached screen shot.
One thing I can't test is if the Order Details table has the right variant SKU for each variant. This is crucial to my business as I use that table to email my distributors so they know the quantity of each variant they need to ship. Please make sure that is coming in right.
Minor Issue
This has been an issue for a while, but it should be fixed. When entering Variant Inventory, you must check one of the variant check boxes or it throws an error. Just put validation check and a popup that says, "You must select at least 1 variant". The DNN error isn't user friendly for a non-programmer. In addition, all of your functions should be wrapped in try/catch anyways. Write the error message AND stack trace to the logs.
Everything else looks good so far. I will continue testing and add to this if I find anything.
Great work!