Hello,
I'm under Win10 and Spine 3.6.53

It's been several times since I observed some weirds things, when exporting from Spine into PNG.

Here's my spine:
 Loading Image
My source images all have 3 px padding.

And, When I export:
 Loading Image
 Loading Image

I was actually expecting Spine would cut the transparent pixels, and trim the image. Because if I go into Photoshop and I trim:
 Loading Image
Then, everything is fine. Check the hand on the right.
 Loading Image

So, why no trim in Spine?

I just realised that Spine might trim but, taking into account the mesh box. Am I right? If so, why not add a parameter when the mesh box are not taken into account.
 Loading Image

Related Discussions
...

3.6 will always take into account the boundaries of the animations, and of each single piece. On the contrary, the beta (soon to be stable) will allow you to set the canvas however large you want (yay, thanks Nate 😃 I'm still so happy about this!) and trim parts of the skeleton out to fit your chosen canvas if you want!