I've been doing embedded work for many years, but have only very recently started working with the Raspberry Pi. I'm planning to build a project that uses a 5" TFT display and a Pi Zero W, and was considering using Adafruit's RA8875 board to drive it.
The RA8875 board uses SPI, however there is a warning in the technical details section that states that this board does not tri-state the MISO pin, with a link to a forum thread that discusses the topic at some length.
I will not have any other boards attached to the SPI connection, but I still would like to know if there are any devices on the Pi Zero W board itself that are connected to the MISO pin. The reason I want to be 100% certain is that with the Arduino device described in the forum thread, mention is made of an SD card, and of course the entire Pi family of boards relies on (micro)SD cards.