Assign Shipping rates to specific product versions

Searched a bit but I’m still not clear on a simple concept.

If I sell a fully assembled product, it needs to go in a box and will cost $20 to ship. But if I sell a bare board version of the same product, it can go into an envelope and will only cost $2 to ship.

I’m probably missing something, but it seems I can only assign a shipping choice ($2 envelope) to a product with all its versions. I can’t seem to say this shipping choice is only for ‘bare board’ not for ‘fully assembled.’

If someone orders “fully assembled” and selects the $2 shipping, I’d be selling at a loss. Do I need to make it “fully assembled w shipping supplement” and crank that price up?

Seems like if the “select products” part of the Shipping Setup panel had checkboxes for to the versions of the product, it would be more clear.

I haven’t found any other way to do similar things, other than to add the shipping as part of the option to have it assembled. So yeah, that’s how I’d do it.

Probably also specify that is part shipping, so the price hike doesn’t scare people off.

Or sell as two different listings.