From inline ordered, named inputs (dynamic formset) migrate to one input type="file" multiple

I have dynamic inline formset of images, where clientside (js) at creation point automatically specifies names and some controls (remove button, thumbnail), so I don't need do it on my view when it saves.

Today I was asked migrate to multiple selection in one input ... At first I thought to create additional

<input type="file" multiple />

then simply clone selected files to dynamically created inputs, but I've read that it is impossible due security restrictions ...

So question is how I can solve this?