I don't ride a recumbent, but after thinking about it for a while, I decided I would ride to the front of the line and stop beside and slightly in front of the front car. If their left turn signal is blinking, I would stay where I was and turn with them. If not, I would signal to them or tap on the window that I was going to turn left ahead of them when the light turned green, and then move ahead a little. If there was enough room I would move completely in front of the first car.

Because I went to the front of the line, everyone has now seen me. If the first few cars are turning left, I wouldn't slow anyone down. If the first few cars are going straight, they can go as soon as I am out of the lane, well before I am halfway through my turn.

To me that is the best balance of safety and utility I can think of. If you are comfortable trying it, please let us know how it works for you.

Tom