The core idea presented involves defining a new SigVersion that would enable the interpreter to alter its behavior for certain opcodes depending on this version value. This methodology leverages the interpreter's existing access to the SigVersion to facilitate differentiated opcode execution without introducing breaking changes to the current system.

The proposed approach has significant implications for how Bitcoin can evolve its scripting language and handle 64-bit arithmetic operations. By utilizing different SigVersions, developers could potentially introduce soft forks that extend the functionality of Bitcoin scripts in a backward-compatible manner. This concept is crucial for maintaining network consensus while allowing for the expansion of Bitcoin's feature set. The commit in question serves as an exemplar of how such changes could be implemented in practice, demonstrating the viability of the approach within the existing Bitcoin architecture.