A new version of Mesen, known as MesenRTA, is approved for Legend Of Kage submissions. It has enhancements designed to give speedrun moderators greater confidence when approving a run. The standard version of Mesen is also still allowed, but if you are a Mesen user, consider this alternative.

It can be downloaded here: https://github.com/threecreepio/mesenrta/releases

And here is an infomercial I made to explain and promote it: