Yes, but for 99% of code written out there there is nothing to gain from faster code due to undefined behaviour.
I am coding since the mid-80's, always been a fan of Algol lineage of programming languages, with C++ being the only exception to it, as it allows many similar features.
Never have I had a situation where better performance thanks to undefined behaviour was an advantage for the use case we were trying to solve.
I think outside games, HPC and winning compiler benchmarks there hardly an advantage exploiting it.
If the solution delivered is within the time constrains required by the customer, any time spent optimizing ms out of the application is just wasted money.
I am coding since the mid-80's, always been a fan of Algol lineage of programming languages, with C++ being the only exception to it, as it allows many similar features.
Never have I had a situation where better performance thanks to undefined behaviour was an advantage for the use case we were trying to solve.
I think outside games, HPC and winning compiler benchmarks there hardly an advantage exploiting it.