djdannyphantom Thank you for your suggestions!

The idea of adding a live record button is interesting. Procreate Dreams is pushing a similar feature, and there could certainly be a demand for it in Spine.

As for a plugins system, there is a related section in the Spine FAQ that you might want to take a look at if you haven't already: https://esotericsoftware.com/support#Does-Spine-have-a-plugin-system%3F

In fact, there is a user who has already created a tool that does live recording outside of Spine and creates a JSON file that can be imported into Spine later. If you're interested, check out this thread: https://esotericsoftware.com/forum/d/16925-spine-pro-vtuber-working-prototype
Although the primary intended use of this tool is for Vtubing, after loading a skeleton data into this tool, it has the ability to record the motion captured from the camera as an animation and export it as a JSON file.

We are not uninterested in adding a plugin system, it would just take quite a while to actually implement, so it might be faster to see what can be done with this method of modifying or creating outside of Spine and then importing it into Spine.