Hi Rahul,
If the business is willing to do Unit costing for each FY then I would suggest you may also suggest to use CJR2 which gives additional functionality that you are looking for.
Please refer to below screenshot where I have tried to compare CJ40 vs. CJR2. As you can see, CJR2 will allow you to plan for each month as you, i.e. manually.
For ease of usage, you may create a cost element group for cost planning in CJR2 and fix the planning layout to 'Form-based planning' so that the cost planning activity becomes business friendly.
Hope this helps.
Best regards,
Aditya
