Question: why are some variants not available in Order Cycle outgoing section?

I’m assisting a shop that has a large number of products, with multiple variants. They have recently switched from a shop with simple order cycles, to use the multi-step order cycles.

In the incoming step, all variants are selected.

On the outgoing step, more than half the variants have become unavailable. There’s no indication of why they’re not showing. All variants are from the same supplier, which is the enterprise that is co-ordinating the order cycle. They don’t have any enterprise permissions relating to them.

What else would make these variants “unavailable”?

Of course, when I give up and ask for help, I find the answer!

This shop has the Inventory feature enabled, and only has 63 variants populated there. I think when simple order cycles were used, the “incoming” selection was copied automatically to “outgoing” in the background, without checking inventory.

I’m not sure how to to best work around, will ask if they still use Inventory or not.