I hope it never IPO's, it is too important to be public for now. Worst case scenario is that it IPO and McKinsey comes in to "streamline" the company ...

Surely Musk would retain control of the board like he has with Tesla

Streamline the rockets, not the company.

Elon has said multiple times that he won't go public before Mars stuff has happened.

Gwynne Shotwell has said they could spinoff Starlink as its own company and IPO it and use that money to fund more Mars projects if they run out of money. But if Starlink is profitable once it is up and running why would they sell it off/IPO? Just keep taking the money over years probably will work better in the long term.

Starship and other Mars projects will be large upfront capital expenses with a lot going in R&D.

I believe Musk would prefer faster returns to speed that up than wait a few years more patiently.

I think its unlikely SpaceX will have an IPO. Elon likely wants to maintain as much control as possible until he gets to Mars. Spinning of Starlink makes sense once its up and running.

Musk has mentioned a few months back that they're planning to have Starlink IPO as a separate subsidiary of SpaceX, or something to that effect.