so i have been playing with the buttons, and the placement of them, and im sure i will come to regret this!!!
my biggest hurdle was trying to turn the 10x7 array that the TCA8418 can provide, and convert that into the 14x5 'standard' keyboard layout that most people use every day (one row of numbers, 3 rows of letters, and a row for crtl/alt/super etc)
I finally sussed it, chop to 10 in half and rotate each side 90 degrees in the opposite directions. Then placing the TCA8418 in the middle of it all and were getting there!!!!
A quick run of the autorouter shows me it will work better this way, i need to spread the buttons more ans other fun. get the feeling i am going to be sick of these buttons by the time i am done with this