Raoden at one point pondered how many different ways there were to access the Dor. Since he thought he saw Shuden glow while performing some ChayShan martial arts. I don't know much about martial arts but I think in Tai Chi "finding your center line" is a thing.
I'm new to the whole Shard thing about Dominion and Devotion since I haven't read anything outside the Sel books. But if Aon Dor and Forgery magic are drawing power, or whatever, from a location like ley line. Then maybe it's possible to draw from your own center as well. Then again, it's possible ChayShan might be stronger in Jindo; we don't know.
It's strange that the seon (plural?) functioned perfectly fine despite the chasm line. They were only affected when their masters were stuck or frozen in an incomplete Elantris transformation. I feel like that's a clue. Like maybe the flow of the Dor comes through their masters, and had less to do with their own Aon being incomplete? Again, I don't know anything about shards or realms because that's all outside knowledge to me at this point.