Shipping plan setup for variants

This is a bit of a drawn-out query trying to understand how best to setup a shipping plan for a product that will have the same SKU’s across most of the shipment and mixed SKU’s for the remaining units.

Here is the situation

I have a product with 8 variants (clothing; size and color)

I have 8 SKU’s with a total of 288 units, so 36 units per variant.

A carton can carry 8 units which does not divide perfectly for the number of units per carton.

The order has been packaged fos shipment like this: For the first 256 units, 32 of the 36 units per single SKU are packed across 4 cartons.

I've created 8 packaging templates under the relevant SKU's and assigned the 8 units per carton with 4 cartons per template, but for the remaining 32 units (I think) I’ll need to have mixed SKU is those 4 remaining cartons (4×8 = 32)

For the remaining mixed units, it looks like I need to add a packing line "individual units" for the left-over variants under the relevant SKUs

Logically there are an additional 4 cartons; 3 of which contain 2 SKU’s(4 units each) and the last contain 4 SKU’s (3 units; 1 unit & 1 unit) , but these will be split under the SKU's as an added packing line "individual units"

I hope this makes sense, and it seems to look correct as I have it setup under step 1 of the Shipping plan, but wanted to confirm this before proceeding.