Is there a way to get OSX Finder to search through .ts (textscript) files?
Unfortunately Quicklook and Spotlight need to know how to look into a ".ts" file. Sounds like they are (essentiually...) a text file but you need a way to tell macOS that.

Over on Stack Exchange there was an answer to a similar question that might be of help to you. It does involve a project on GitHub and may involve some programming skills on your part to make it work with ".ts" files, but it seems like a start, at least...