I have a 2.4" TFT display from mcufriend. Have this working with no real issues plugged straight into my Arduino Uno. Later i want to transfer it to a mega wired via a breadboard to give me more IO. Thus as a trial I tried connecting the display plugged in to the breadboard to the UNO. However i just get a white screen (TFT on board reset button seems to work). I have copied wire to wire from the Uno to the breadboard/TFT, I have even redone 3 times with the display on different parts of the breadboard. Any ideas?
Your display can plug directly into the MEGA2560. It will work fine with most libraries. It will just be slower. You have plenty of GPIO pins available on the bottom headers. And you know that the display has secure connections with EVERY pin on its shield.
In principle, connecting all 28 shield pins via flying leads to a breadboard should work just fine.
In practice, there are a lot of wires to go wrong.
Incidentally, I made a Protoshield that receives all the pins from the shield and routes them to the "best" pins on a Mega. All the interconnections are soldered. The display + adapter + Mega is physically robust. And runs the display at maximum speed.