You could shorten the time in flame if you move the tip of blue inner flame to the case neck. I'm not sure how you could know whether it's less accurate or not. As long as they all go through the flame the same amount of time they should be essentially the same.
I use 650 degree Tempilaq on the side of the case to assure it doesn't reach this on the bottom 2/3's of the case wall. Time varies between 10 sec and 15 sec depending on caliber (longer than what I see in many videos).
Certainly not as accurate as an AMP but for my purposes it works.