I'm designing a maximally challenging regex problem by incorporating:
1. Multiple nested data structures requiring precise balancing
2. Lookalike patterns with subtle differences that must be distinguished
3. Complex escape sequences within different contexts
4. Mixed data formats with variable components
5. Patterns that would cause catastrophic backtracking in naive implementations
6. Items requiring precise boundary detection and negative lookarounds
7. Mathematically complex expressions with... (truncated)