Pop quiz results time!
Both A and B are 1/6 snapped and recorded seconds after each other with no individual changes to the beatmap beforehand.
But Ephemeral, that's disingenuous of you. You did this to trap and humiliate people! You phrased the question like they were both snapped differently from each other.
It is a little bit, but it was done so with a very important point. The pop quiz illustrates not a failing in any of the people who choose to try it to correctly identify snapping within a map, but the near-impossibility of relying on human senses for such incredible precision, and the incredible number of factors in any particular situation that can thwart such attempts.
A few people in the modding discord correctly identified to me in private that both videos were in 1/6. One person did so after investigating each video for per-frame, per-pixel differences. This suggests to me that those particular people took the effort to consider an alternate solution to the obvious one that was offered and sought to substantiate differences they noticed in the videos with real, tangible evidence. That is the kind of problem solving that I want to see more of in modding, instead of blind reliance on what 'feels' correct.
This extends to using peculiar snaps like 3/16, as well. It may 'feel' correct, but it is musically incorrect, and it is at best, a pale workaround to a much greater issue.
The effective difference between 1/6 and 3/16 is minute. Almost impossibly minute. The reason that it subjectively sounds and plays superior to many of the people who have expressed as much in the thread is that with the current beatmap's imprecise timing (due to its approximated bpm), the greater precision of the 3/16 split allows for note placement closer to the actual sounds of the beatmap. 3/16 allows for in essence, correction of incorrect timing.
The 107.96 bpm approximation that Ishukan has is the direct reason why 3/16 is thought to be required. Any map with an approximated bpm would demonstrate the same effect of feeling "more accurate" if notes were placed on a considerably more precise interval, where individual notes can be tailored to match sounds at a much higher level of allowed deviation. This does not make their timing correct - if anything, it exacerbates the problem at higher levels of play such as when using mods like DT or HR, and those timing inaccuracies compound into significantly greater problems. A good example could be made in halving a map's BPM and doubling the lowest level of snapping used to map it with. You wouldn't do that, so similarly, you shouldn't do it here, either.
pishifat and Shiro have both suggested alternate timing using the splice method. Indeed, 1/6 within their timing schema is both the musically correct and technically correct way to approach a track composed in this general measure. The two of them are both very experienced and highly skilled timers - perhaps among the eminent tiers of excellence in their respective fields. To disregard their expertise would be very silly indeed.
Thus, from the observations outlined earlier and the reasoning above, I must insist that the splice timing is applied and the snapping adjusted to 1/6.
I may have said earlier that I was willing to compromise on the matter, but after further consideration and the subsequent example as portrayed by the "pop quiz", I no longer feel comfortable relying on the measurement of a handful of people's ears (and being at the mercy to the dozens of potential confounding factors thereof) in comparison to hundreds of years of musical theory and first-hand knowledge of how timing functions in this game.
If the mapper does not wish to capitulate on this front, then there will be no recourse but to leave the map in the graveyard until he decides otherwise. That, or someone presents sufficient evidence to suggest that my line of reasoning is faulty, and that two of the game's best timers apparently do not know what they're talking about.