Are you using kiln treated timber ?
Your noggins need to pick up the edge of the board all the way along
If it was me I wouldn't have bothered putting any in
What you have done seems ok but they need to be continuous supporting the whole board, not sure about the course of bricks through the blockwork though BC round my way don't allow that, cold spot but don't worry it wont fall down.
It's not much heavier than 12.5.