[RP2040] Clock Reconfiguration

[kleinai]

I'm working on an RP2040 project where I need to reconfigure the clock after doing some start up tasks. I have an I2C clock chip which needs to be programmed prior to switching over the clock source.

I don't need any fancy features like updating PWM during the switch or anything dynamic. I need the clock chip as a USB reference which I'll initialize after the switch. Also the ring osc. is unsuitable for UART as I've found out.

Is there any easy way to support this? Any simple workaround?
I probably could program the clock chip but I don't want to waste the one-time programmable ROM and this leaves more options in the future.