Hey there Dirtlizard,
Congrats on the MXT PRO!
I will check and see where a Large Cent comes up on the VID display in the Relic Mode. I would anticipate in the mid-80's where quarters hit giving a RELIC LABEL of BUCKLE.
Remember that when you're in the Relic Mode with the MXT, the target ID LABELS will be relic oriented labels rather than coin. Target ID Numbers will be the same whether your are in Relic or Coins/jewelry, but the labels will be different. In relic, there are 5 general categories; HOT ROCK, IRON, BUTTON, BULLET, BUCKLE. They are in ascending order or course, with HOT ROCK / IRON being least, then your conductive range of Button (low-range), Bullet (mid-range) and Buckle (high-range). If you didn't dig those 'buttons' and 'buckles', you probably should have.
Generally, as you are learning a new detector, it is advantageous to dig lots of different targets to see what targets correlate with the signals your detector gives. As you gain more experience and proficiency, you will get to where you can CALL a target/signal before you dig with pretty good accuracy. Still, the only way to know for sure is to DIG and recover.
Rich (Utah)