You seem to be asking for double-buffering, which it doesn't support. I wondered if you can switch from RGB interface
(ie video) to GRAM and back, but the datasheet doesn't look promising, they are separate modes.
If you can drive in 16 bit or 18 bit parallel you can update the RAM upto 130 times a second in theory - at 100ns cycle time. 130 FPS
is faster than the LCD pixels can respond I believe.