I have not ever tuned a set of dual single barrels...... I always go bigger.
A lot of folks talk bad about itc's ...... I don't get it..... just a carb.
Dual singles like to idle on only two cylinders. The balance tube helps, but if everything is perfect it don't make a diff. But it does hide or smooth out tuning problems. I would not hesitate to use a balance tube.... it would have to be fairly large ID though.
Here is a link to some help I googled up for you.
https://www.wayoutwestie.com/aircool...cooled-engine/