Moving away from Squarespace, what should I know?

As much as I love Squarespace, the community, and the web designers I've come to learn from in building my website on the platform, I unfortunately need to leave Squarespace since I have a high-volume digital products shop, thus I need more advanced e-commerce features that Squarespace currently does not have. 

I have already begun the process of moving away from Squarespace, coding a new website on a different platform, having to move products manually since they are digital as well as blogs, and other information. However, I don't plan on moving absolutely everything over before I launch the new website. My question is, once I leave Squarespace, will I still be able to log back in and reference the old website to get information from. Simply exporting all the information from the old website to the new website, unfortunately, doesn't work because again, I am a digital products shop which Squarespace doesn't offer great support for. 

What else should I know in the process of leaving Squarespace in regards to what it will look like on the backend for me after transferring my domain?

31 minutes ago, kds_on_ss said:

What else should I know in the process of leaving Squarespace in regards to what it will look like on the backend for me after transferring my domain?

Disconnecting your primary domain from the Squarespace website will only affect visitor access. Whilst your website subscription is paid, you will have exactly the same access the 'backend'.