Just in case others are looking. I'm using an Xorcom Astribank w/ 2 PRI channels and 8 FXO / 8 FXS. My two configured trunks are the PRI channels.
In the new FOP2 manager, under button config, trunks, I had to input info in the "Extra Channel" field to get the DAHDI channels to show.
It was detected by FOP2 as DAHDI/g1 and DAHDI/g2. In Extra Channel I added "DAHDI/i1" and "DAHDI/i2" respectively and it now works.