I wish someone made a tube type VV that took perhaps two batteries and was made/regulated like our box mods.. a non boost type. (I don't know the terminology) I may get the Madvapes VV box mod for a backup - I like the idea that it does not have the limitations of the LavaTube or the Provari but will handle anything from 0 to 7 volts but I really wanted a tube type. ( with a meter Ha Ha.. I want it all)
Check out the Buzz Pro or Infinity Pro should be the same. I can vouch for the BP, holds the voltage as it should till the battery dies with very little dropout under load, longer battery life and it's less current limited than the Provari or LT. Doesn't have a meter but you can pick up a screw on meter if you really want for $15ish.