I'm wondering whether anyone has a reliable and up-to-date suggestion for how to use the GPIO pins on a Raspberry Pi with Pure Data?

Wiring Pi seems to be pretty much deprecated, as far as I can tell. I tried to follow this suggestion for using retrograme to generate keypresses but I couldn't get it to work: https://forum.pdpatchrepo.info/topic/11564/how-to-use-disis_gpio-for-rpi-button-input-alternatives/4

Any other options that I'm missing?

For anyone stumbling onto this thread, including a future version of me:

I made an extremely bare-bones but functional example that takes button inputs from Raspberry Pi GPIO pins and sends them to Pure Data, I’ve put a minimalist example up on my GitHub along with some documentation: https://github.com/yannseznec/gpioOSCpd

I think it would be pretty straightforward to do GPIO outputs too, I just don't need to right now so I didn't bother!