Thank you very much for your feedback. I've implemented fixes that I believe should solve those two issues.
First off, the bone attachments. This was due to a new implementation I added to improve parity. You see, the `flip_model` property just inverts the scale on the x-axis. This is fine, but seeing as how everything else flips by, well, flipping, I've decided to introduce new code to make it so that bone attachments would rotate instead of having their x-scale inverted. Unfortunately, my implementation introduced a few issues:
- Failing to consider that some might actually want their models to be flipped for varying reasons.
- I based the transform calculations off the base PaperSkeleton's transform and not its `billboard` node.
- My math also had some other mistakes, with the rotation actually being significantly off.
These all should be fixed in the new update. There's an `invert_x_scale_when_flipped` property implemented, as well as fixes for the other two issues.
Secondly, the visibility bug. Very simple fix really. You see, I initially had the PaperSkeleton node constantly check if the Polygon2Ds' visibility were toggled. Instead, now I have it change during the `NOTIFICATION_VISIBILITY_CHANGED` notification on each PaperPolygon2D. Unfortunately, I neglected to initially define this visibility upon instantiation, of which it now does, so consider the bug fixed. Also, I tweaked it so that it references `is_visible_in_tree()` instead of `visible`, so that its visibility can be toggled as a group when put underneath a child of a node that's not visible.
If there's still something wrong with any of these feature, please let me know.