Yes the diameter is huge, I have come to accept its loveable bullet shape. I'm not buyig a 28 mm tank,.
Still think it is a way better vape in quality than the Ephro I was not at all impressed. It's probably the best option I guess. I found the machining to be rahter poor (personally_) and the 22 mm version (whcih I have) IDK, it was just the suck for me.
I suppose it's your best option. It's not BAD exactly but it is super MEH.
Otherwise, you go to dicodes. If you can afford that, it is your best bet they make some killer tubes....at povety inducing prices.
Anna
I'm fine with the EHPro vape (same model as you). Is it Dicodes good? No, of course not. But one costs $20, and the other.... "More".

Nowhere near the build quality either, but for a cheap imitation, I still feel it's quite good. I LOVE my Dani V3 tube, and I LIKE my EHPro. Again though, that's like comparing apples & cauliflower.