Which peninsula sink vent strategy is best for this situation?
Thanks a lot for the illustrations! I'd go with Option #4 where the sink connection and trap are done right. Trap parallel with wall and drain immediately elbowed. Trap is as low as needed and no forgotten odd in-wall setup while hanging a serving shelf type of situation.



In the case of a Garbage Disposal (GD), you'd use the GD itself as the elbow. Or, like the picture, you'd send that to the back ASAP as well.



Now, if you want to go nuts, literally, and get away from cleanouts or slip joints. Then, you'd glue-in union fittings under the sink so the entire drain start is solid-state and drops out for snaking. The picture is for using the trap as your elbow, but displays the union wonderfulness.