Picked up an 8MB SPI PSRAM on sale a little while ago and have been excited for the possibilities of having that much extra room to do microcontroller-y stuff with. I wrote a simple driver for it, you can find it at: https://github.com/MarksBench/mb_PSRAM_64Mb_SPI
I’ve only used it with a Raspberry Pi Pico (RP2040) since that’s the only MCU I have that’s running MicroPython, but it should work with other MP-capable devices that can use a hardware or software SPI bus.
Writing and reading 64Mb over SPI is not fast, but it works!