How can I keep a task synchronized to the same column in two projects?
Because sections are specific to projects and are not shared between projects, you can’t accomplish this directly.
So what you can do is use a custom field (you can also use a tag) to in essence link the two projects together, and then create rules in each project.
I.e. in Project A you create a rule like "If task gets moved to Section ‘In Progress’, set the value of custom field ‘Status’ to ‘In Progress’. Then in Project B, you create a rule like "If value of custom field ‘Status’ gets changed to ‘In Progress’, move the task to the ‘In Progress’ section.
Note that you have to make sure the custom field is a global one; that is, it lives in your organizational custom field library.