It is important to keep in mind that as the wind increases the upper jib leech will open up more, and as the wind decreases the leech will close. Thus, the forward crew must realize that if the breezes is on and the jib leech is at the ideal position, when the breeze drops, or the boat slows due to waves, that the leech will close and the jib will be over-trimmed. So the jib must be eased. Obviously the converse is true for a building breeze.
Therefore, the forward crew must always be on the ball ensuring that the jib trim is accurate all the time.
The Lightning jib has several controls which will effect its overall performance. The halyard or wire tension, the cloth tension, the jib lead and the sheet tension. It would be best for you to consult with your sailmaker's tuning guide for that sail's specific settings. However, I will offer some observations.
While sailing this years NAs, the primary jib adjustment was the sheet tension. Each day I would set the jib lead for each tack, because each tack had a different wave angle necessitating a different setting, and I left them there. As for the wire setting, it would be set so that the headstay was a bit looser than the wire at all times, and the cloth was set so that the scallops just disappeared. Once these were set, I did not adjust them.
But I adjusted the sheet tension frequently. The main goal of jib trim should be to keep the top of the jib working as efficiently as possible, without closing the slot, or killing the flow over the leeward side of the top of the jib.