First, welcome to PPG, and thank you for your offer! Now, as for your question:
The "bonded" path -> the continuation of BG1 NPC is really interwoven within the mod, so it is rather difficult for me to point it out, but it is possible. Let me see:
- in ToB part, nothing, except for the dreams(the end of O#Xan25 file - if you've played the mod, you'll see).
- in SoA part, all banters that have Global("O#XanRomanceActive","GLOBAL",2) or Global("O#XanMoonbladeExtinguished","GLOBAL",3) in them. I could only point parts to you, though there's probably more:
BO#XAN - 1068-2096 3658-3756
O#XANJ - 600-780 1170-1371 4551-4572 2043-2408 and other bits and pieces - you'll find more if you compare .tra file and .d file and find variables I've indicated (O#XanRomanceActive=2)
Then, the end of O#XANP and O#XAN - 117-193.
Again, if you've played the mod at least once with every path, you'll see more.