[Tharre]

It's a question of what tradeoffs you're willing to make. If you're making a professional product then sure, but I've checked the chips you suggested and the cheapest one available on JLCPCB seems to be the LPC1820FB at $6.5. If you fuck up a revision or two at 5 pieces each that gets expensive rather quickly for a hobby project.

It's a shame really that ULPI is such a complicated interface, at least compared to RMII or SDIO, otherwise you could just buy a high speed USB ULPI phy and use it with the RP2350 via PIO. Eben even mentioned at some point someone working on a PIO ULPI implementation, but I'm assuming that went nowhere because they couldn't make it work reliably.

An alternative approach I've been considering is using a ch32v305 as a "smart" USB-HS bridge, and connecting the RP2350 via SDIO to it. The problem with that of course is you have to implement most of the USB stack on the ch32v305, and the documentation on those chips isn't great to put it mildly.