That's beautiful and what a great choice of fabrics you made!
Peggy Martin has a method for getting the seams to line up she calls the Three P's. Pinch/Peek/Pin.
Pinch the seams together so they line up perfectly. Peek at them to make sure by holding them together with your fingers and opening up the seam to be sure they are perfectly lined up, then pin through the 1/4" mark. This works well for me.
I think your block looks great and after it is quilted no one will notice a tiny bit her or there.
Would you share the name/link to the block?
Watson