Welcome to the community @MattOlen 

I don't believe it's possible to switch off shipping confirmation emails in Shopify without first enabling "automatically fulfill order's line items".

The way I handle this is to let Shopify send the shipping confirmation email which contains details of the product(s) purchased. Then in a post-fulfillment Klaviyo flow (triggered from the fulfilled order event) I add a delay to allow for the product to have arrived with the customer (or close to that expected time) before the first post-fulfillment flow email is sent. The content of that email is more of a welcome/order thank you and highlights USPs/brand values etc. The subsequent flow emails tend to be informational, review requests, and cross-sell/upsell if the contact has opted-in.

A couple of considerations on this subject worth mentioning:

• Order confirmation and order shipped emails are transactional, therefore, you don't want the customer to be able to unsubscribe. Transactional emails sent by Shopify don't have an unsubscribe. However, Klaviyo must always have an unsubscribe unless you flag them as transactional and they are approved as such by Klaviyo. If any of your post-purchase flow emals contain non-transactional content they will be regarded as promotional marketing. More info here: https://help.klaviyo.com/hc/en-us/articles/360003165732
• You can use a Klaviyo template (that you an edit for your brand) to replace your transactional emails in Shopify if you want to keep things consistent across both platforms. You can find various Shopify transactional templates here https://www.klaviyo.com/templates/themed (and filter for Shopify). They contain the relevent tags to pull the order data from that Shopify.

Hope that helps.

Andy