Booting the RP2350 from UART

The RP2350 is a nice microcontroller from Raspberry Pi. Recently I thougt about a new project, where a lot of PWM channels would be needed. The RP2350B has 24 PWM channels, which is a lot - but not enough. I would need at least 33 PWM channels, and also some more GPIOs, so the RP2350 alone isn't enough. So I thought about a port expander... But what about using a second RP2350 as a port expander?