I'm curious, if you don't mind me asking, do you not enjoy the Kayfun X, or just not recommend it because you haven't tried it yet? Perhaps there are some characteristics you find off putting?If you haven't already, take a look at the kayfun Lite [plus] and kayfun Prime. Both are excellent MTL RTA's.
The KFL airflow goes from a very tight MTL to a max of 1.2mm via the adjustable Aerokon AF design. It's a bottom fill RTA.
The Prime has six stepped AF options (1mm, 1.2mm 1.4mm, 1.6mm, 1.8mm, 2.0mm). Top-fill RTA with JFC.
I have a couple of each. My kayfun lites are from 2019, those have a max AF of 1.8mm. SvoëMesto discontinued the KFL19 and replaced them with the newer KFL's with the Aerokon AF system. I bought an Aeorkon upgrade for one of my KFL19's, wide open at 1.2mm it's a really nice/smooth MTL.
Just started looking at newer Kayfun models recently (because I really like this KFL V2+ clone), and some of them seem divisive, so thought I'd ask.