When using the left hand as the main hand in the skin configuration options, putting an item in the offhand will render the item in the GUI on the left side, while the box will be on the right side (as it should be). Tested on Minecraft 1.20.1, Quilt 0.19.4
When using the left hand as the main hand in the skin configuration options, putting an item in the offhand will render the item in the GUI on the left side, while the box will be on the right side (as it should be). Tested on Minecraft 1.20.1, Quilt 0.19.4