If I can be sure the sensor works when I'm on top of the left portion, them I'll sit over the left one. But I seem to have more luck with the center one, so that's usually what I aim for.

As for peope cutting the curve as they make lefts from my right, if I'm on my upright bike I can usually move over a little, but I will usually just glare at them and hold my ground. On my trike I find it impossible to move and it can be scary knowing you can do nothing more than brace for impact if a good indignant glare doesn't have effect.

I've never had anybody insist on running into me in this scenario, however. They always know they are in the wrong when they do it.

This actually happened to me the other day when I was on my Vespa. I held my ground and scowled at the guy. He got the hint. So far holding my ground and scowling has always worked on any machine I've used.

Buses on the otherhand often have no choice, but they won't run you over. They will simply stop and inconvenience everyone until people back up.