svoemesto has always catered to the MTL crowd first and foremost. The OG K5 was their attempt to cater to all vapers. MTL'ers complained it wasn't MTL enough which led SvM to making the MTL AF Pins Kit. SvM has since tried again to grab some RDL/DL market share with the newer K5's. I have an OG K5. My younger brother traded his OG NarDA for my K5...but...since then he snagged the NarDA back.As you know - you put me on to it - I have the KF 5 squared SE. It's a DL atty and I like it but I get the feeling svoemesto were catering to a market they don't quite get.
The 810 dt setup is weird and I run mine with a 510 adapter but it doesn't feel quite right. It's also a huge hunk of 25mm metal that doesn't fit some of my fav mods.
I've been enjoying tighter draws lately and did a fair bit of research about the KF 2019 Lite v 21 (Plus). Seems like most agree that the new Aerokon af control is a better design than the nylon grub screw used in the 2019. Better flavour and smoother air.
The SXK clone also comes stock with the 4ml dome cap.
The KFL21 and KFL19 actual build decks are identical in size to my SvM Kayfun Prime's. Vapdivrr compared and measured both decks. Building and wicking is the same on the Prime, KFL19 and '21.
You might want to look through the KFL19 and KFL21 thread. Authentic Svoemesto Kayfun Lite - 2019 & 2021 Version
There is much info on the KFL21 at the end of the thread. Start on the last page and work back. A couple folks who have the KFL21 and a couple who upgraded their KFL19 decks to the new KFL21 deck saw no improvement in flavor. One or two did notice improvements.
I was going to buy a SvM KFL21 Upgrade Kit for one of my KFL19's but decided against it for what may, or may not, be an improvement. The KFL19 is a very serious flavor RTA with it's small chamber/chimney design. KFL21 chamber and chimney are the same size.
You might also want to look through the Prime thread. It has several videos, photos and many tips for building and wicking. In fact there is more info on wicking in the Prime thread versus the KFL19/'21 thread. It all applies to the KFL21 and '19. Authentic Svoemesto Kayfun Prime
The AF in the Prime goes as high as 2mm. I have no problem pulling a restricted DL on mine but mainly use the Prime's and my KFL19's MTL.