TWebDBResponsiveGrid - child array in Dataset

Hello,

Tried with web core 1.6.2 and 1.7.0 Beta.

I need to retrieve values from an array within a sub-object of the dataset and I can't find a way to do it. object attributes and sub-objects attributes are ok, it's only with arrays of objects that I can't reach :

here is a cleaned part of my template

<img src="img/(%Produit.PHOTOS[0].Chrono%).(%Produit.PHOTOS[0].Hash%)" alt="product">
<div>(%Produit.Libelle%)</div>
<div>(%Produit.Description%)</div>

I obviously tried (0), (1) and [1] just to be sure...

When debugging JS, i can see my dataset is available
Capture

But the img part is not resolved, there isn't even an error.
When viewing the source of the resulting html code, i see this

<img src="img/(%Produit.PHOTOS[0].Chrono%).(%Produit.PHOTOS[0].Hash%)" alt="product">
<div>Baguette traditionnelle</div>
<div>180 gr.</div>

What am I doing wrong, or is it even possible ?

Sorry for double post, but does it mean this problem has no solution ?