I think the lack of air feed from under the coil on the Themis will produce less flavor and vapor. Air coming from under a coil gives it 100%. Side only will lose some flavor.
You install mesh wire, not coil, in a mesh edition Themis.
It is like a metallic net that holds your wick from the above and thus there is no heating from the bottom. In this case, I don't think direct bottom AF is a good idea - you will get dry hit pretty soon.
Take the example of OBS Engine Nano which solely works on side AF - it has very good flavor and can be cloudy if you open the AF fully. Trust me bro, it is not "the direction of AF" but "the coverage of heating area by the AF" that matters!
In fact Zeus has no direct bottom AF too, but it is the best RTA so far for you and me, right?