I use fairly tight MTL with the Xeta, I use the smallest lower airflow insert under the coil, I think it's a 0.8mm single hole, I ran a 1mm drill bit through it by hand to open it up a little, and I use the medium sized chimney insert, I find it great like that... (I vape 1.8ohm 3mm coils at 10.5watts)
Using both the smallest inserts it's way too tight, I couldn't imagine anyone using them together, but the option is there if you want it crazy tight...
Edit: also: with the above setup I get basically no condensation, under and around the boro tank stays pretty much bone dry, there's no need for condensation plugs or such.... I think due to the fairly low airflow with MTL and the even restriction through it with the 2 restrictors, condensation just isn't an issue... (unlike with the Crossbow or Insider V2 I used for MTL previously, they were quite bad)