On one hand, I love my highly synergistic madness decks, spell slinger decks, dredge decks, what have you. On the other hand, I am a little sad that the occasionals aren't really what you're supposed to do when you try to win, at least not the more niche ones and the buildarounds. I'm so torn. I love casting Faithless Looting and discarding a couple Rootwallas, and I love going off with Talrand, or having Ninja of the Deep Hours on turn two. On the other hand, I also want the dorky and weird decks to be able to keep up with my synergistic archetypes. Not sure what to do about that.
Full disclosure: I haven't had experience with implementing occasionals in my cube. But I'm seriously considering it. I've read all of the discussions, including your experience, and I like what I see.
I can compare it to retail draft rares that aren't format defining bombs. A lot of them are constructed plants, others are just weird. Usually, key uncommons are much more thought after, because they could be archetype-defining, not unreliable oddities. But sometimes someone has fun with those weird cards others pass. I remember draft with
Lupine Prototype and other rares going circles around the table. It looks like the floor is 2 mana do nothing without proper support. But one guy made it work in his slow soup deck without it being all-in madness aggro. It was surprisingly refreshing as a finisher.
As I see it, it's a way to make 700+ card cube impression while having 360 card cube. Many environments have 15th picks that are fun in the right deck, but rarely pursued by drafters. Which is arguably inefficient use of space. So we use those slots for hundreds of cards instead of a dozen. Low opportunity cost for a possibility of maybe having a surprise sometimes. But not all of the time. japahn's idea was giving up your designer control.
If the goal is to make occasional module more alluring, it might make sense to put the best niche payoffs off the main list, like
Vengevine and
The Dawning Archaic. Those shouldn't be universal power outliers, just extra seductive for the right deck. Holy grail cards for a designer make you rethink your strategy without requiring changing the whole cube. Those are hard to find of course. Since we assume core module has all the structural support, the "fun" stuff could be in occasionals, instead of core. Like, I was drafting UR control, but now I'm excited to switch to prowess aggro. Or I was in RG madness, but this card makes me want to do slow BRG graveyard grind. Core makes sure your cube works, occasionals give it quirks.
I'm purely theorizing at this point. Just my views on how it could be done.