Can't get enough DMA memory on ESP32: assertion "matrixUpdateFrames[1] != NULL

Thanks for that explanation, it does help.
As you said, what I lose is color depth (not actually so noticable) and brightness (much more noticeable).
“lsbMsbTransitionBit of 7” is not a happy place to be at indeed, now I’m back to 3 due to my panel size (96x64) and refresh rate (>120Hz)

lsbMsbTransitionBit of 0 requires 49152 RAM, 39960 available, leaving -9192 free: 
lsbMsbTransitionBit of 1 requires 24576 RAM, 39960 available, leaving 15384 free: 
lsbMsbTransitionBit of 2 requires 12288 RAM, 39960 available, leaving 27672 free: 
Raised lsbMsbTransitionBit to 2/7 to fit in RAM
lsbMsbTransitionBit of 2 gives 100 Hz refresh, 120 requested: 
lsbMsbTransitionBit of 3 gives 191 Hz refresh, 120 requested: 

Looks much better.