That's not a bad suggestions. I'll see what I can do.
This feature has been already implemented. Settings, "Seekbar hovering". Alt+E if you use the default shortcuts.
I can replicate the problem. I also found the source code of 2.51, it does have similar source code. I'm trying to continue the work of Kameleon. I'm not a programmer. Founding a solution could take a long time.
You're using a fork of subtitle workshop, ask your questions there. That's why they can't answer your question here.
I could look at the source code of the UroSoft, if provided. It would help. The phrase "Urosoft versions" is ambiguous.
Project fails to load for version 6.3.4
Copying text with empty lines into subtitles can break the .vtt format
I just tried various scenarios with "Errors and settings" but I wasn't able to replicate the error. Please provide subtitle file and the line that gives problems. Does "Errors and settings" use stock settings? If not, please provide which settings that are altered that gives problem. At this moment, I can't work further without more details.