Binary instrumentation tools are widely used to facilitate the development of hardware and software systems. Traditionally, these tools are designed around a fixed Instruction Set Architecture (ISA) specification. However there is a shift in the architectural community towards open ISAs, whose key feature is the ability to add custom ISA extensions. The lack of extensibility in traditional binary instrumentation tools limits their capacity to adapt to these evolving ISAs, thus hindering their ability to analyze and modify binaries built for open ISAs.