Yes, steel tube couplers can be used in scaffolding projects with limited access to scaffolding boards or planks. Steel tube couplers are versatile and can securely connect tubes together, allowing for the construction of scaffolding without the need for traditional boards or planks. This makes them a practical solution in situations where access to such materials is limited. Additionally, steel tube couplers provide stability and strength to the scaffolding structure, ensuring safety and reliability.