Technically yes. By that, I mean that one would need to know what's going on to get to the multiple addresses. Knowing what the mod is supposed to do, I can go through the order process and successfully order, select different addresses, and get multiple packing slips that are correct. It's just some of the verbiage that might confuse the customer.

Since Multi does not work with One Page Checkout (OPC), the customer must go through the standard three-step checkout. Even one more, if actually using Multi, to confirm it all. So, here's the two situations.

Situation #1

When the customer selects Checkout, they are presented with Step 1 of 3 - Delivery Information. This is Shipping Information and the customer is told that their order will be shipped to the address on the left or they can change it by clicking on the Change Address button. Actually, if shipping to multiple addresses, any changes done here will need to be re-accomplished on Step 3 of 3 to accurately reflect the multiship addresses.

includes/languages/english/checkout_shipping, line #16, defines the text
Code:
Your order will be shipped to the address at the left or you may change the shipping address by clicking the <em>Change Address</em> button.
You can have the mod installer change the text in the core file, merge a changed file with the core, or place an override in includes/languages/english/YOUR_TEMPLATE/checkout_shipping.php. Any method would work with the override being simplest for newbie installers.

Suggested text:

If you are <em>only shipping to one address</em>, now is the time to make sure the address is correct. If you are shipping items to <em>multiple addresses</em>, those addresses will be entered in Step 3 of the checkout process.

Situation #2

If the customer gets to Step 3 of checkout and realizes they need to buy additional items, increase a quantity or decrease a quantity a warning is triggered from includes/languages/english/extra_definitions/multiship_common.php. The warning is of two sentences. The first lets the customer know that the product was added, or increased/decreased in quantity and will ship to the Primary address. The second sentence of that warning is
Code:
You will have the opportunity to change this during the checkout process.
If this file is only called when multiple addresses are selected, perhaps the second sentence should be
Code:
You will have the opportunity to change this during Step 3 of the checkout process.
The warning correctly does not appear on a deletion of an item as the customer would not have to adjust a deleted shipping address.