Hi,

Thank you for preparing the gif animation! Actually, there is a similar issue here :
Non-destructive offset+shift for secondary motion. #153
https://github.com/EsotericSoftware/spine-editor/issues/153

Those suggestions on the issue ticket are a bit different from each other, but they want to simplify the workflow to make follow through or overlap. In that respect, the features under development may help solve the problem. The details have not been announced yet, but we hope you will look forward to them.