Option to clip transparent pixels on Export Persona

[Tazintosh]

Good morning everyone,

 

I'm actually intensively using Affinity Photo/Designer for a web project.

My design include many embedded documents for a greater flexibility.

But here's my problem: I like to set my embedded documents with a canvas much bigger than the element I need in my final composition

For instance, the following illustration is my embedded document (vastly unzoomed). Its canvas is bigger than what I need on my final design. In fact, I basically just need the book and its shadows. But having a bigger canvas, allows me to better "view" the book in an "environnement". When I'm done, I just deactivate the background and move around my layer, scale it (a lot) etc. into my final composition.

 

Then, comes the time of exporting the book image so I can include it in my html.

At this point, I —need— my book to be cropped to it's minimum. I need to clip all transparents pixels.

Sadly, on the export persona, if I select my embedded document and create a slice from it, the slice is obviously surrounding the exact bounding box of the document.

Of course, I understand this, but I would love to be able to check an export option "clip transparent pixels" and ends up with something like this automatically:

[Tazintosh]

Bump 2, the Return. :D