Impact of Change in Prorate Convention in Asset Category

I have a requirement to change prorate convention on a specific category so that new assets will use that changed Prorate convention. But simultaneously my existing assets should continue to use old prorate convention. I believe this can be achieved by just changing prorate convention on asset category. It will only default new prorate convention only on new assets and will continue to use old convention on existing assets. Kindly correct me if I am wrong.Cha