Attaching file is an example to see the difference between 100vh and 100% computed values.

On my pixel 3, on Chrome the difference is 143px (note that the initial-scale value is 1.0 and the minimum-scale is 0.39 (the minimum-scale here is not the one in specified in the meta viewport though). If the minimum-scale is 1.0, the difference is 56px on my pixel 3.

So, it looks like the vh height should be "the ICB height + 56 / 0.39" (56 / 0.39 = 143).

But things are not so simple as far as I've tested. In cases where the minimum scale is dynamically changed, it's inconsistent. I am going to two cases where the minimum scale is dynamically changed in different ways.

In this case, vh units value is also changed in response to the minimum scale change.

In this case, vh units value is not changed in response to the minimum scale value.

Does the 56px correspond to the dynamic toolbar's height?

Yes, I think the 56px (in CSS untis at resolution:1.0) is the dynamic toolbar height on pixel 3.