Interesting project, writing a useful PHP extension is an every web developer's dream.
However, the licence choice is weird. It's really asking to be MIT. Any company bigger than 2 people pays attention to that. Most web projects are proprietary. GPL‑v3-or-later is not appropriate for proprietary/closed-source.
Also, the README is lacking a nicely looking comparison chart, motivating people why they should use your project instead of just running grep in shell_exec. I'm very unlikely to run the benchmarking scripts myself. You have to convince me why your project is better than the established industry practice.
However, the licence choice is weird. It's really asking to be MIT. Any company bigger than 2 people pays attention to that. Most web projects are proprietary. GPL‑v3-or-later is not appropriate for proprietary/closed-source.
Also, the README is lacking a nicely looking comparison chart, motivating people why they should use your project instead of just running grep in shell_exec. I'm very unlikely to run the benchmarking scripts myself. You have to convince me why your project is better than the established industry practice.