19c: Best options to turn a single instance into 2 node rac with minimal interruption?

Hello,

We will have following a database migration, a 19c single instance database running (no-ASM); but there will be a future requirement to alter this to run in a 2 node RAC with ASM; and I wondered whether anyone had any best practices on doing this?

Options being considered:

1. Creating a 2 node RAC physical standby; but it could be risky if we had to switchover before we were ready.
2. Creating a single instance physical standby which we would convert to a 2-node RAC prior to switching to use it as the primary.
3. Converting the single instance primary into 2-node rac

I have found information about using DBCA to convert and also about running a single instance in a RAC environment (disabled or enabled).