I have been using alass for many years and I still think it's unbeatable when it comes to quickly and precisely syncronise subs. I admit there's perhaps a 1% of the cases where the tool didn't perform well, mainly because the subtitles are from a different editing (more/less dialogue) or something.

I have asked the question on the alass github already but got no answer.

What I am after is a reporting tool. Something that I can scan my library with and detect a level of synchronization. I believe alass does this internally somehow but it's not able to report only. Such a function would be amazon to identify video/subs buried in my library where the subs are not good enough.

Is there any alternative method you are aware of on how I could script-up a subtitle quality check?