Has anyone ever tried asking NS to add the newly purchased module to the Sandbox account rather than Prod? This is to avoid refresh.

You can make the provisioning request by account explicitly if it’s a bundle. If it’s not a bundle, and is part of your product code you’ve purchased from NS, it will show up on prod as soon as 1 day. The module may not be enabled; but it’s presence could alter e.g. PDF forms if you’re using basic template. Suggest creating a support case if you’re a NetSuite customer and negotiating this with customer support to determine your specific options; if you don’t have support, your account mgr.