Conversion from Composition to Regular

A client wishes to switch from a GST composition scheme to a regular dealer scheme from July 1st, 2020, having filed all returns up to June 30th. Key questions involve the application process, feasibility mid-year, handling stock on hand, and the possibility of applying retrospectively. While some advice suggests conversion isn't possible mid-year and requires waiting for the next financial year, others recommend filing an intimation in Form GST CMP04 and reporting stock in Form ITC01 prior to the change.