I’m using LVGL with the i.MX RT 1052 boards and I’m pleased with the performance.
This is for a 480x272 with touch controller. It has the advantage that the CPU is able to transmit the data directly to the display which is fast compared to use an SPI connection. SPI works well for me on smaller displays too.
If selecting a display controller type: I like the SSD (Solomon Systech) ones which (at least some of them) have a ‘dual RAM’: you can write to the second RAM of the display and then switch the content: that way the update is ‘immediate’. You still will need time to write the data, but at least it is less visible to the human eye.
On a side note: if using the Teensy, keep in mind you won’t be able to debug it (at least the ones I have used).
I hope this helps.