Well, there's a fair bit to consider with 3ds to be fair, especially since it has an entirely separate update line from the rest of the versions (Primarily being 1.2.4 with a few changes and additions from 1.3.0.4, along with a shocking amount of exclusive weapons and armour along with 3 exclusive bosses)

Recording has varied methods depending on the model. New 3ds users can just stream it wirelessly to their PC with a bit of homebrew working, but old 3ds users are stuck with either capture card or the dreaded method of pointing a camera right at the device. As far as I know, Citra emulation doesn't have much to put it over playing it on actual hardware (it may even be a little bit of a disadvantage), though I'm a little blind on the emulation thing myself.

Something to note is, Old 3ds users ARE stuck at 30 fps and a world smaller than the current gen small worlds, though New 3ds users do get 60 fps and the option for current gen equivalent small worlds. Not sure if that'd effect the most but hey, I felt like it's worth mentioning.

The 3ds version of Minecraft, with it's exclusives, isn't applicable to any other category in the game due to it's unique update line and exclusive enemies and bosses.

Perhaps an All Boss category could be made for this version of the game?