Is there any other way to make strings local in these tags or is it possible to control which dat file the local strings shall be read?
There is/was a technique where you could have a set of your own .dat files (one per locale) in the same folder as your script and PS would use that automatically. I never got it to work but I never tried very hard; somebody else might have a clue.
However, I believe that using custom .dat files would only happen of $.localize is set to true. If that is the case, then you're out of luck as the <javascriptresource> and <terminology> is parsed out of the file at PS startup. It doesn't execute the script so $.localize cannot be set.
You're best bet is to find strings in the tw10428.dat file that best suit your needs. That should work for most typical strings but I doubt that javascriptresource.name is going to be one of them.