Here is something else to consider, and something that is actually quite valuable: Even if you just rotate to the front, spend 3 seconds there, then pull off, you are still helping the pace line.

Each rider is providing a draft, and the more riders you have, the better the draft for those in the back. If you can't pull, you are still at intermediate points of the pace line, providing a draft to those behind you.

I would rather have five other guys in the pace line, with one taking a 2-3 second pull, than have just four other guys.