Not only is there no personalization box, the link photos to variations doesn't work in Pattern. I show 10 different colored shirts and in Pattern they do not display as they do on Etsy. Also you cannot add google tags to the head tag, we have no access to the code.
I love that it hooks up to Etsy for shopping cart and stats, but that is where it ends. 😞 Might move it and then point products back to Etsy for purchase...thinking it over....
They haven't updated one feature since the launch of Pattern. Many of the newer features do not exist, like the variation photo links, videos, it does not index on search engines, etc. It's an abandoned project that I think they are just collecting as income with no real UX management.
The advantage of sending people to your Pattern site instead of Etsy is that you only pay processing fees, not the transaction fees.
@stufforama stated it perfectly.
What you see is all you'll ever get with Pattern, for better or worse. So if you don't like it now, don't expect it to change.