Hi Daniel
This is not the default scenario, for traceability most workflows are asking for clearly separate steps and datas that refer to the user that produced them. Therefore, process devleopers will create save points/tasks, wherever it could be ok to switch the actual working user.
However, if you need your custom logic, where users more or less can save and share data at any time, you can achieve it easily by using the BusinessData feature. Its a repository of data flowing through processes, and can be controlled via API, so you can invent custom save actions without actually switching tasks.
https://dev.axonivy.com/doc/10.0/designer-guide/data-modeling/business-data/index.html
Best regards,
Reguël