Is the Breakout Garden I2C + SPI compatible with Raspberry Pi 5?
It should be fine, yes. 👍
Hardware wise yes. Software wise, all depends on how hard it ends up being installing into the Python Virtual Environment. Plus the Pi uses the RP1 chip to interface with the GPIO. That may or may not cause issues? I haven’t connected much of anything to my Pi 5 GPIO. I do have oodles of Pi and Pico Breakout Garden stuff in use here. I love this ecosystem. :-)