Thinking about trial ends

Mixed Single Club quarter final this evening. My opponent one of the up and coming lady players. Format is best of three sets, each of seven ends. Hugely important to get a good start. Lose the first couple of ends and you're in big trouble.

That's caused me to think hard about trial ends. Normally each player rolls the jack to their favourite length to judge line and length. Normally players favour a medium length. But I don't. And I'm reasonably confident I can get both line and length more accurate in the first few ends on my favourite maximum length jack than most opponents. So what's the benefit of using my trial end to give the opposition practice on a full length jack? Doesn't it make more sense for me to roll a shorter jack?

Seems to work well. My jack, play a short length, my opponent a medium length trial end. First 'proper' end and the jack is at maximum length. My opponent is short, three to me. Keep the jack to maximum five out of the six ends we play in the first set. At 8-1 to me there's no point playing the seventh end.

Set two and the opposition's jack. Much closer this time. There's huge danger as we play the fourth end. I'm down 1-3. If my opponent puts a couple of bowls on the jack the remaining two ends may not be enough for me to recover. Manage to score three. Another two in the next end. One end to go and it's 6-3. My opponent scores two. My set 6-5 and through to the semi final with a 2-0 win in sets. Here's the scorecard.