Actually, I had this idea the other day for a very simple mod... sort of the big brother to the EZ Watt 35. It would be an 80 watt internal battery mod that is versatile (for different tanks) and simple. No screen, just LEDs... a vertical row of 8, each representing a 10 watt increase (10, 20, 30... 80) and another vertical row of 4 (different color) for 2 watt increase (2, 4, 6, 8 / 12, 14, 16, 18 and so on) Would need 12 LEDs total. Two small buttons (one for left row, one for right row) It could be called the "LED Zeppelin"... OK, bad joke
EZ Watt 80 Watt should be fine. Maybe (just to be different) offer 2 tanks (because it's so versatile) one lower watt coils for MTL and one higher watt coils for DTL. I never know if I'm crazy or brilliant LOL
P.S. please make sure ALL tanks have airflow control.