As you pointed out, you might be a bit more rushed coming from Sound Inside than you would be coming from Moulin Rouge. But at the end of the day, you won't have any trouble making it to FLS on time, regardless of which show you choose.
So ultimately, I'd say go with whichever show you are more interested in seeing.
EDIT: Just saw the post above. I saw Moulin Rouge after opening and it definitely didn't run that long. Not sure what would account for the show extending 10-15 minutes after it's frozen. Unless the intermission has just gotten REALLY long.
Updated On: 11/8/19 at 11:41 AM