Combining print on demand with other products in one shop

I have a shop on my site selling products that I ship out personally but I also want to add Printful print on demand products. Is it possible to sell both from the same shop and if so, how does it work in terms of billing and shipping information that the customer receives? Basically, what would the process look like if a customer bought 2 items - one shipped by me and another from Printful?

I need an answer to exactly this question!

Did you have any luck..?

I've been looking for an answer to this as well. What do you all do in the interim? Sell on multiple shop pages? 

There's a paragraph on this page: https://support.squarespace.com/hc/en-us/articles/9052125217293?input_string=possible+to+sell+both+physical+products+and+printful+%3F

I ended up removing all my print on demand stuff with Printful because the profit margins were so low and I wasn't totally happy with the quality of the products.