I definitely agree with your reasoning about commander. It can become so tedious. The problem with Cube is that the draft portion can take ages, as well, and players who don't know all the cards can feel exhausted after the draft and have low motivation for building a deck and playing.
I guess I really appreciate 60-card magic for its simplicity, in a way. Your deck has a game plan that you can fairly consistently pull off, the number of different cards is lower and it's all in all a tighter gameplay loop that still offers plenty of complexity. The huge disadvantage is that it is extremely hard to have a balanced and fair metagame on a budget in nearly any 60-card format. The second someone starts buying singles or netdecking the arms race begins and many casual players will be left in the dust.
Sultai Emissary and [[Bayou Groff]] have really good synergy. The Groff is a great manifest target and it can sac the emissary if you play it normally, but I don't quite see how I can make this work as a deck. It seems most people tend to want to abuse manifest by manifesting something huge and flickering it, but I feel that that line of play is a little bit too convoluted to be worth it, although it is nice that [[Soul Summons]] and [[Ephemerate]] are both white.
I think the trick to playing the Emissary is to have a decent volume of OK manifest targets in the deck, some sac value stuff and not overthinking it too much beyond that.
[[Scythe Tiger]] and [[Rogue Elephant]] are also good value manifest target, but their ETB effects are not so nice if you have them in hand. Perhaps in a sacrifice oriented deck they could be worthwhile if you just sac them as they ETB to trigger something like [[Mortician Beetle]]? Flipping a manifested Tiger in response to a removal spell is quite sexy, though.