I have verified the above scheme works. I managed to updated my existing single-owner pool with 2 owner and a separate SPO account. You can find my test pool at Cardano PoolTool - The most comprehensive staking statistics for Cardano on the web.
In this process I also created a diagram to illustrate the relationship among all keys, certs and processes. Hope it helps. I will probably write a blog to flesh it out.
Also another thing that is probably worth sharing
- I used Daedalus wallet to create 2 accounts. One is delegated to some random pool, while the 2nd one is not.
- I used extraction tool to extract stake key and payment key from those 2 accounts and used them as the 2 owners
- it turns out I only need to register stake addr for the 2nd account. No need for the first account since it was already registered by Daedalus when I delegated it out for the first time.
