The short version is I’d make these changes;
1. Shorten triangle to 4” finished
2. Reshape triangle to 45’ angle at top point, it’s not equilateral triangle.
3. Buy plastic template for this angle
4. Make paper templates for 2x 3x 4x 5x, to cut 1 piece for multiple triangle.
5. Limit size of quilt to 68x48”
6. Make mock-up for placement of rockets/jet’s/arrows whatever they are.
7. Have .5 yds for each accent fabric. Don’t prewash, it uses every 1/8 inch.
Because Jessica made such fabulous panto patterns, I expect only good things from her.