I modified the source files of version 2.3.0 so that they are compatible with PHP 7.2 and lower. (Yes, I have time )
You can recover the source files on my GitHub:
Do not hesitate to send me your feedback.
Personally, I use it in production with PHP 7.1 and locally with PHP 7.2 and I have no problem.
Hope you find it useful.
Have a good day !
Also, we already completed the PHP7.4 compatibility and will be available with the release of Forma 3