Yes, as IGC.ToolKit (Premium) license is lifetime it is still possible to use the tool. To do it is necessary to request as change to MU.ToolKit (Premium) which excludes editors dedicated for IGC Server Suite files only.
It is also possible to switch back to IGC.ToolKit (Premium) once Server Suite files license subscription is paid up-to-date.
Switching from IGC.ToolKit (Premium) ↔ MU.ToolKit (Premium) is free upon request.