Activating Carrier Calculated Shipping on a development store

I’ve just created a development store for a client so we can test some features related to Carrier Calculated Shipping (CCS) / checkout rates api
https://help.shopify.com/en/manual/shipping/setting-up-and-managing-your-shipping/enabling-shipping-carriers

Speaking with Partner support, they’re not able to activate CSS on a development store as it’s not one of the eligible plans.

How do we test CCS features for clients of ours before making them subscribe to a larger (potentially unsuitable) plan?

Ignore this - After some testing… CCS is activate by default on development stores it seems.