With a DNA40, the only time you should see "temp protected" before the wick is dry is when you've got a build problem, or the most common reason, your set wattage is MUCH higher than it needs to be. With a DNA, "temp protected" is basically telling you that it can't put out the requested wattage because it's already hitting your set temp, and has to pull back on power quite a bit.
For example, a 0.15 ohm 30ga coil in a Kayfun, 6-7 wraps on a DNA40. Set wattage to 40 and temp to 420, and you'll for sure see "temp protected" very early in the pull, and you'll see actual applied wattage somewhere in the teens or lower. Same setup, but reduce set wattage down to 20w, you probably won't EVER see "temp protected" as long as there's juice in the tank. That's because the delta between requested wattage and actual isn't so large. But the actual quality of vape between setting it to 20w with no message, or 40w with the message, is identical.
Yihi pretty much said screw that noise, just let them know when we think the wick is dry, and let them vape with no worries before that.