Hey bud, welcome. So JFP 2.0 looks for scripts with names that matches the video title. If you want to watch videos with fillers the best course of action would be to change the name of the video to match that funscript file name, then change the name back to it’s original once it’s done.
There is another player on this site XTP, which allows you to choose a different named script. Check that out and see if works for you.
https://discuss.eroscripts.com/t/xtplayer-cross-platform-tcode-sync-osr/4496/6