It will fit fine I have the ego-c passthrough and it works ok doesn't do as well as I would like on that maybe the smaller vivi will. I would suggest getting a twist works really well on that and you can adjust it for different types of flavours. I have kinda noticed some flavours are really temp sensitive and where one will taste very burnt another will be just fine. That is why I like the twist a lot when I want a very small "footprint" setup. Definitely get one of the cones and even the collar lanyard attachment but remember to file the opening a bit for the button or it will stick. That makes the whole thing look very nice together.
Syl