Yesterday I said:
I'm still not quite happy with the display. It shows datagrams received when the change is great but gentle control doesn't show up. This keeps the display from interfering with the car control but doesn't make for good debugging feedback.

Today I've replaced the program ESPLMouseAP with an improved version. Instead of updating the display when there is a big change between datagrams, it now updates the display when the display itself is much different from the last datagram. This way, gradual changes ARE displayed eventually.

The display tracks input datagrams much better, without monopolizing the processor. A couple of lines of change and a better result.

In my next design, I'll know that writing to an I2C display with an esp8266 is SLOW. Using an SPI display takes more pins but should be faster. Something to try.