Sorry for Google Translate, but it's better than my English.
Mode VV depends on the resistance of the spiral, i.e. it gives an interesting effect similar to the prehit on SS spirals. This is unattainable on TC and WV, it is not achievable even by heating curves, which are still not in DNA. In one version of MyEvic (for Joytech / Wismec motherboards), specifically versions from MicroSur implemented a simplified VV mode in the original VW firmware. It just does not allow changing the voltage after the initial resistance measurement. It's quite interesting in terms of heating dynamics.