Connect a form control to a different list?

no it's not possible.

if the target is just to show some data from the other list, you can use calculated value control and lookup() funtion within the formula to query data from the other list.

‌ ‌ ‌ other list‌ ‌ ‌

Hi, 

Maybe you know if this information is still vaild, or maybe there was some new developmend that include that funcionality?