So, when searching for information on SPI graphics displays on the Raspberry Pi, I found this nice custom driver that allows for faster framerates on SPI displays by sending only changed pixels rather than doing a whole refresh.
20200303/DuckDuckGo raspberry pi spi graphics display
20200303/https://hackaday.com/2018/10/21/blazing-fast-raspberry-pi-display-driver-will-melt-your-face-then-teach-you-how/
20200303/https://github.com/juj/fbcp-ili9341#how-it-works
Also, the driver documentation lists the compatible display controllers and the products that use the compatible display controllers. Great for making the buying decisions.
Please note that the driver custom codes directly against the low-level BCM2835 interface the assigned SPI interface, so you may not be able to use more than one SPI device through slave selects. In that case, you’ll need to wire your project to use SPI0 for the graphics display and SPI1 for all other SPI devices.