Printful integration with multiple Shopify stores

[Forever]

Please help me determine if I need to create a new Shopify account to have 1 Printful account work with multiple stores. I am getting conflicting information on whether my current setup will work or not, so I am scared to go much further with developing my second store before I know the answer. 

To elaborate, I have 1 store already fully setup and launched using Printful for products. I am in the process of creating a second store in order to test another URL and a different product mix. I need to be able to link to the same Printful account. I have received guidance that I cannot have the same Printful account work with 2 stores on the same account (even though each store has its own plan). I also received some advice that it can work, they just can't assure me that it will. Very frustrating that neither Shopify nor Printful can give me a confident answer on this.

I need advice whether I should scrap my work on the 2nd store under the same account & start from scratch a completely different account and store.

As a side note, I was able to add the Printful app to the second store and it appears to work. But with all the feedback and info I've seen I am not confident that this will work long term, so can't count on what it "looks like".

Please help!