Continue as you have been doing keeping 1/4 as you have. Any alterations will affect the whole quilt. I was told just after I started quilting to even keep to the same sewing machine to piece a quilt as there could be thread differences in the seam. 1 thread on each piece makes a big difference over 60 inches. This was my excuse to buy more sewing machines. One for each project. Quilting also keep to one machine as stitch length has a variant as well.
Your work is beautiful so remember the class info and finish this super quilt. Can't wait to see it.