General charging is recommended to maintain 20%-80%, charging to 100% easy to damage the battery. It is easy to charge 100% using DC charging, so I generally use a level 2 charger, and I can make an appointment to charge about 80% in a few hours.
Recommend reaching out to Ford's customer support again, specifically asking for escalation, and also checking if there's a software update or specific setting within the truck's settings that might be preventing the scheduled charging feature from working.
Installing a charger at the farm might be the most practical solution, especially if you’re leaning toward the F150 Flash for its pricing and features.