I have some suggestions.
- Make sure 21700 cells fit, not just 18650 cells.
- 10S3P isn’t very big.
- Make it long. 48"+
- Make it wide. 11"+
- Give yourself more space for wheelbite than you think you need; move the truck bolts further from the foot platform and out to the ends.
- connectors epoxied through the body of the deck so zero wires enter or exit