Hrmm, I'm now setting the cursor position based on what's returned from parinfer, and it seems like it's often wrong. I sometimes type ni esrever elihw gnitresni ni tnedni edom.

Seems to have been an off by one on the cursor position (both line and column).

maybe because vim is 1 indexed?

Yeah. I actually fixed that Sunday, but I didn't rebuild the plugin, apparently. 🙂