My Wismec Predator 228 started acting strange lately. The resistance reading goes up and I'm suspecting the 510 pin's spring / travel is the problem. If I push the atomizer toward the mod the resistance goes back to normal, but after I take my hand off it goes back higher. I don't think I'm suffering from the infamous problem with the negative threading. Anyway. I think such a sophisticated firmware should have a VV mode included. It's the most absolute way to control the power without relying on questionable ohm readings. In my case I would pick a voltage that vapes to my taste and let it be. Right now I keep adjusting the wattage to control the voltage as my ohm readings vary from 0.45 to 0.55 (Kanthal). Let me know what you think about it and please focus on the VV mode as a suggestion, I'm not asking for help with my mod's issue.