Blockchain technology has emerged as one of the most significant innovations of the last two decades. Since its proposal in 2008, blockchain applications have expanded beyond financial transactions to sectors such as agriculture, education, healthcare, and the Internet of Things (IoT). However, these applications face several limitations, particularly in IoT environments. This paper addresses some of these challenges by presenting improvements to SpeedyChain, an appendable-block blockchain. To enhance SpeedyChain, this study proposes a storage and indexing structure, which significantly improves the system’s reliability and reduces the volatile memory used. The proposed structure aims to enhance efficiency and robustness in managing, saving, and accessing data, being designed to handle the high transaction volumes typical in IoT environments. Experimental evaluations demonstrate substantial improvements in the system scalability and overall blockchain performance. These results highlight the potential of our approach to significantly enhance the functionality and efficiency of blockchain systems in commercial IoT applications. By optimizing SpeedyChain, this study contributes to overcoming existing limitations and sets the path for more scalable and reliable implementations of SpeedyChain.