110 sounds more like a speed rating, not a load rating.

Numbers are the load rating. They use letters for speed. 93H 108T etc,

No a user cannot adjust the preset TPMS pressure values. You need the Tech2 - the dealer scantool - to do this. It's not super expensive. Or pay the people who have said tool. The dealer's $125 quote is industry standard 1 hour labor minimal charge, you won't get it done cheaper. Also if the tire size was changed, you should ask them to enter that in Tech 2 too - to adjust the wheel circumference so your speedometer is correct. This won't result in an extra charge.