Normally, to access Maniac Mansion, within the Macintosh version of Day of the Tentacle, a player would interact with the computer in Ed Edison's room 5 times.
The MacGUI is still present when Maniac Mansion is accessed. This includes the Save/Load system, Preferences, etc.
This video shows what I'm talking about: https://youtu.be/N5AZY3tNFW4?si=eUa7urqPGUq94Ojc&t=160
But, with ScummVM, the Maniac Mansion files need to be extracted from the "Day of the Tentacle Data" file, added into a maniac sub-folder, and then added as a separate game entry in ScummVM.
If added as a separate game entry, Maniac Mansion loses those MacGUI features and acts like the normal DOS v1 version of Maniac Mansion. This extends to ScummVM outright quitting versus being brought right back to Ed Edison's room in Day of the Tentacle.
If ScummVM can read/recognize the files within "Day of the Tentacle Data" to load Day of the Tentacle, is there any way that it could load/recognize the Maniac Mansion files too?
This way, it could preserve/replicate the way the Macintosh original loads Maniac Mansion.
Looks like this was also mentioned in Ticket 15066.