Okay, it's Monday and I have not had enough coffee yet today. Sorry, I am blind!!! :-))
Unfortunately, on the 7C, the only place to see the trim changes is the front of the transmitter that you are seeing. There is no indication of percentage or amount of change and you cannot reset the Trim without doing a total reset to all setting and mixes on that model.
Only the older 9Z, and the 12FG, 12Z, and 14MZ have the options you are looking for.
Sincerely,
Krysta
Product Development & Support Specialist
Futaba Service Center USA
[email protected]