[Kingtyprz]

Does anyone know a way to connect Kodi (installed with Libreelec on Raspberry Pi 3 B+) to my 3.5 inch LCD display (Note: it is not HDMI)? The display is from Uctronics (https://www.amazon.com/dp/B073QG5YV6/) and is pretty much just an average touchscreen display. I don't even care if the touchscreen doesn't support touch, I just want the visual to work. Any help will make things easier.
-Many thanks, Kingtyprz

!NEW UPDATE! (Thanks to popcornmix and noggin for help)
I cannot seem to boot Kodi on Raspbian (every time I change the GPU to 256mb, the Pi boots into Emergency Mode). I've tried other 16gb USBs, only to see the same resulting script.

I have heard of (and looked up information on) fbcp, but I'm unaware of how to use it/how it works. Do I just run the script on the fbcp Github, or is it more complicated? And should I run Kodi on LibreElec or Raspbian? Again, any help will be appreciated.

[popcornmix]

Not trivially. The firmware can't drive an SPI display, so you need something like fbcp to mirror the display.

Note:
480x320 is probably too low for kodi skins.
SPI displays have a fairly low update rate so GUI and video playback may not be smooth.

I've not tried this, but it gets asked about occasionally so may be best to wait for someone who actually has this running to reply.

[noggin]

Not trivially. The firmware can't drive an SPI display, so you need something like fbcp to mirror the display.

Note:
480x320 is probably too low for kodi skins.
SPI displays have a fairly low update rate so GUI and video playback may not be smooth.

I've not tried this, but it gets asked about occasionally so may be best to wait for someone who actually has this running to reply.

This may be better than fbtft+fbcp these days for some displays https://github.com/juj/fbcp-ili9341 It uses a number of techniques to increase refresh rates.

Probably not great for video playback but very worth while for retro gaming...

For a small, neat LCD display I think you are better off with a DPI rather than SPI connected display.  The Pimoroni HyperPixel (now just released in updated form) might be worth a look - it's available in touch and non-touch versions AND is driven natively by the GPU so has no need for special drivers for video display, just a modified config.txt.  It does use all the GPIOs pretty much though.