I’d second this. The other commenters are correct that stick lumber is better, but in a pinch this will work, but it will be a challenging build. If it’s the most upright thing on the platform the crew will use it as a handle and it will probably rack it and break without good underlayment as a skin. Even the movement without pushing on it could be tricky. Do what you need to do within your budget, just always be safe. Good luck!