I really appreciate your assistance in an area that is rapidly diverging from the main thread (and from the hardware platform as well!!). My excuse it that I've been feeding back bug reports/fixes to libraries like Bodmers, fixes which will probably apply to most of the Adafruit derivatives (check for issues raised by g8ecj - that's me!)
I'm using an stm32f4 which includes an FSMC (Flexible Simple Memory Controller) so all the hardware is handled for me!!
I'll play with the timing in case the 9488 is vastly different to the 9486.
Again, many thanks.