Hi Engineer. You are correct, and the sealtbelt reminder chime can be turned off without FORScan. The instructions on how to enable/disable the chime are on pages 37-38 of the 2018 Owners Manual PDF version.Not sure about this particular case since my seat belt settings are stock, but just for general knowledge I can say that in some cases things we can set through Forscan are just settings for things the manual gives us other ways to change. I have no idea in this case if that's the deal, but I know some of the things I've seen in Forscan I've thought "I could just change that the normal way". So for instance there might be a BCM setting and an IPC setting for something. Usually the BCM setting would be the actual state, and the IPC setting would control the ability to change the settings from the dash.
OK, I've got Forscan 2.4.2 beta, OBDLink MX+, connected laptop to OBD, reading codes etc OK.You need to use FORScan to edit your car's AsBuilt data. Oreo's post contains the correct bits to change. A basic Android app cannot change AsBuilt data, nor can the FORScan Android app for that matter. You also need an OBD-II adapter that supports Ford's MS-CAN network - like the OBDLink MX for example.