Since the SDS100 doesn't turn service types ON if a particular service type is not used in a Favorite List,......
That's not correct. Whether a given service type is enabled, or disabled, is set either in your Profile in Sentinel, or via the menu when making changes directly on the scanner.
Just because a given service type is not present in one or more of the Favorites being scanned does not men that that type is turned off. If a Service type is not used in a Favorites list (or in the portions of the main database being scanned if using your location & range) you will see, only a dotted line, and cannot toggle that type on or off.

Since that service type is not currently in use on any Favorites list, (or main database channels as defined by your location & range), you see only the dotted line.
In this screenshot, the Corrections service type is present on one or more active lists, but is not enabled:

No channels tagged as Aircraft, Business, or Federal are present in the lists being scanned, so you cannot toggle that type on or off.