Customize the variables outside the Camunda Task filter

I have a use case where the Task variables need to be displayed in the tasklist LHS.
I know that i can add variable key and label on the Task filter and display them on the task.
But, my use case requires more flexibility so that every other task in the tasklist will show different variables. The filter will remains same, since that is used to filter based on assignee / group etc…

I am thinking of to store taskId and the custom variables outside camunda and inject them to filter/filterId/list response, but that will be a huge performance hit.
I need a better alternative to implement this.