Can we use Indirect projects for Billing purpose with proj planning and control implemented?

Dear Experts,

Is there any possibility that we can extend using same project number created as Indirect type, for project billing purpose?

Because we wish to use project billing now for eligible projects but there were a lot of projects already got created earlier as Indirect.

With new project billing implementation now, it appears that, we need to follow below approach, but involves a lot of adjustment or transafer activities. Please advise if any easy way of achieving this, as we are also introducing 'Project planning and control' along with 'Project Billing'.

Since the project type for existing (indirect) project types/