Affinity 3: Use size of single Artboard

Hi!
It's been a while since I used FF for the last time (in PS), but as far as I remember, in PS the plugin did use the size of the document itself as the output size of the image FF generated, or, alternatively the size of your selection, right?

While FF 14 seems to generally run in Affinity V3, it doesn't seem to run well with Artboards in Affinity. I have several artboards in my document, and the size FF generates is always the bounding box of all artboards (so it's usually huge in my case). You can see this size in the documents details, for example in the top bar of the Pixel Studio.
I understand that Artboards don't exist in PS, and I could live with making a rectangular selection of the artboard in which I want to insert the FF content, but it still uses the size of all artboards together.
Any way around this, that I'm not getting?
Cheers!