Will there ever be support for 16bit ParallelPort? Or am I now pushing my luck? 
The 2.4" LCD is nice but it is a bit small for some applications. Some of the larger displays need a 16 bit bus…
Not planned to be added but you can easily do so using RLP.
From what I understand, don’t know if this was solved, is that there is a significant delay calling RPL functions. So calling and RPL function to just output something in the pins will not be efficient.
Might rather just register access?
No this is not correct. Calling RLP with no arguments is about as fast as calling any native method. The more arguments you add the slower it gets but it is still hundreds of times faster than using register access or C#.
What you need to do is call RLP.Write16bit() with an array of 100 bytes instead of calling it 100 times with one byte, make sense?