Line Linking To Fix Subtitle Flickering

Hi, peeps. Recently, I started looking for a way to deal with the annoying time gap subtitle creators seem to use frequently especially in English Web-rip/Web-dl releases that causes flickering between lines. They usually keep 500ms gap between lines and it's annoying to look at. Fortunately, after looking for hours, I found out that Aegisub seems to have a feature called Make Times Continuous (Change Start) or (Change End). The option let's you link the end of the first line with the start of the second one using either the end time of first line as the start of the second line or vice versa. However, this feature cannot be used on all the subtitle because it doesn't have an option that let's you assign the gap period you want to make continuous which means it must be done manually. I wanna know if there is a tool that can do this. It doesn't matter if it's online or offline.