This is really strange. After rebooting my computer, the intros now work in ScummVM (for the first time for me ever) and I'm able to reproduce the hang. I'm not sure what's going on, but at least I can try to narrow down the music issue now.
Yes, this patcher version (both the original and this new bug-fixed one) only patches the music to repeat immediately. I didn't want to create 6 more file diffs, 3 for the Windows patcher and 3 for the DOS patcher, since that's a lot of busywork just for an alternate version of my patch. If anyone cares to have versions with 20-, 40- and 60-second pauses between repeats, the regular version of the patch (with those variations in it) can be found at PCGamingWiki.com.