So glad it seems like you've come to some sort of agreement with your son.
The scant 1/8" seams probably do need to be re-worked, but the other ones seem fine to me. Gives it a bit of a modern touch. If any of the blocks are too out of square, you could always slice on an angle & add extra wonky pieces to square it up. I'm sure it will be beautiful, so as long as your son's happy, all is well... And that grandbaby of yours is adorable!!!