Eventually I hope to add theme support so that links can look how you want, but that's not a feature that I'll be working on super soon.
The affinity is just treated as a new character position. When caret moves through that position is doesn't "move", but instead draws tail differently. So it's just normal arrow key with one extra state to move through. That extra state only happens at formatting boundaries, so generally the cost isn't too much.
The affinity is just treated as a new character position. When caret moves through that position is doesn't "move", but instead draws tail differently. So it's just normal arrow key with one extra state to move through. That extra state only happens at formatting boundaries, so generally the cost isn't too much.