Ha, how ironic... So I did it last night. It was too high, I planned to redrill the 4 bottom holes, and use the top 4 as the new bottom - easy...As long as it isn't a candidate for /r/TVTooHigh
Then late last night whilst watching a film craning my neck... I remembered the part that bolts to the TV itself, has multiple holes, now some might assume that's for the different VESA sizes, anyway, I remembered there was some adjustment.
Cue early morning removing it and adjusting it, now it's perfection, and I didn't have to redrill the holes/touch the wall bracket!
I'm calling that a win!