As far as I know, the only American vendors currently selling the Young June Version 1.5 Lavatube (with resistance checking, 3.2A limit, and a tube designed to fit most protected 18650s) are SmokeForPennys and CrystalClearVaping. I got mine from CCV.
All the other lavatubes available now from American vendors---regardless of body style and finish---are from L-Rider and contain the Version 1 internal electronics (with the 2.5A limit and pronounced loaded voltage drop-off).
The new Version 1.5 has some quirks because of its pulsed circuitry (when measuring with an inline digital voltage display, the unloaded voltages read as all over the map, and loaded voltages won't read at all---when connected to an atty/carto, the inline meter just flashes dimly, indicating PWM circuitry). Those quirks don't adversely affect performance at all, however. In my estimation, the V1.5 is rock-solid and runs rings around the V1.
I own many VV mods---including 8 Madvapes linear VV boxes, 4 Ken's Boxmods VVs (linear and vari-cool), a Shan B. VapeCore Splash linear VV, 2 Maximum Vapors evercool VVs (a 3AA box and a Woodie), plus both a BuzzPro and an iPro). The Young June Version 1.5 Lavatube performs as well as any of them---hits just as hard with all the various carto/voltage combos I use (which max out for me around 5.5 volts---I have no extra-high resistance atties/cartos or 3.0 ohm dual coils to test at 6V). In fairness, I can't absolutely guarantee that there's no voltage drop, since I can't measure that, but judging by real-life experience, it sure feels like I'm getting whatever voltage I set. I conclude that the claimed 3.2A limit is indeed true.
While I can't speak to long-term durability or reliability, my first week of heavy use of the V1.5 has been terrific---far beyond any skeptical expectations I had based on the many troubles people reported with the V1.
I have a SmokTech VMax coming soon from the recent co-op group buy on another forum, and I'm eager to see how it "stacks up" compared to the Lavatube V1.5---meaning stacked dual 18350s bucked design versus single 18650 boosted.