I constantly come across the names V1-V4, but am still not sure if that is a version or brand or what. I mean, are these versions of some pen? Searching for it, I can find several pens that use that suffix. How do I find the correct "V2" that you are talking about? I feel dumb😛.Try a V1 or V2, $15 isn't much to waste in case you don't want to gamble more cash.
Oh - and cartridges? Do you sterilize them at home too?