Stigma wrote on 08/05/17 at 04:59:56:
Where is the objection to the extra 2D board?
It disturbs the opponent since s/he will wonder if you're going to use it to analyze, maybe when they are away from the board. It disturbs the opponent since s/he will wonder if you're weird or just doing it in order to distract. It goes against the spirit of not using outside sources of information, when there are already enough exceptions to that principle in force.
I take it you are conceding that the rules currently don't allow what you want to do, since you no longer seem to be arguing against that.
I've already explained the purpose many times throughout this thread and if I took the time to do so in this level of detail, it clearly matters to me and possibly others. I've tried getting used to 3D representations by using them online and ~100 official rated OTB games. I still feel a little handicapped by it and it's one of the reasons I haven't played OTB much lately.
To call a 2D board an outside source of information is not reasonable unless you think the official board is too because that's all it is (just a slightly different representation of the same position to accommodate both players). In that case, we should only play blindfold chess.

I'm not conceding that it's against any rules till official clarification is given. It's clearly not allowed to test variations on a secondary board but that's not what we're talking about. In fact, the consistent position would be that this is a case of "de facto acceptance" since what I'm requesting is a subset of something already allowed in a much more complex form and with greater abuse potential. It would just be tiring to repeat every point even if I still hold it.
That's an incredibly general and indirect use of the word "disturb." It's basically saying that their own para thoughts disturb them and it's somehow your fault. Maybe they suspect me of being an engine user because they saw me make a lot of good moves. Is my good form disturbing them?
Anyway, others (and tournament directors) would see you. Any time you make more than one move on either board, it would be really obvious you're cheating. Someone would only have to see your fingers touch two pieces without capturing and they'd instantly know without looking at the position.
You could also say the same thing for the main board. What if you analyze on it when your opponent leaves and after testing 2-3 moves, you put it back? Remember, you'd always have to put it back for either board or the cheating is obvious. Even if you do it on the smaller board and your opponent doesn't notice at first, he will when you press the clock and try to make a move on the secondary board (especially for captures). If you refuse to make one it will be suspicious that you all the sudden no longer want to use it. If you do, the position will not make sense.
I think these concerns are far-fetched and someone with the mindset to cheat would be pretty stupid to do it this way. Stuff like this has the risk and immorality of cheating with chess engines and only a tiny reward. At best, you get slightly better analysis (compared to vastly better from engines as well as a near guaranteed win vs a human opponent) and yet you take an enormous risk in an open setting.
Remember too that all these criticisms apply to the Monroi or PlyCounter too but are waaaay stronger against them (yet they STILL got approved by the major international chess organizations). Unlike this chess set, the opponent often won't be able to see the PlyCounter or Monroi screen. Computer screens are much harder to see at an angle and unlike for the chess set I'm asking for, you can pick those devices up and go to the bathroom with them (at $360 no one leaves it hanging around). A pocket chess set costs ~$10.
You could input the correct moves for half the game and then, in the critical position, you could go and elaborate on the main line in the bathroom. Alternatively, you could go and show a higher rated friend since it's an actual board representation, not just algebraic notation. Even if they have no undo function (it's extremely likely they have this feature), you could just fake moves on your small screen for the rest of the game. Unless someone asks to see it, they're unlikely to be able to decipher it from the standard angles. In fact, you might even use it only in front of your face and then put it in a weird way on the table. An opponent could always walk around to your side and inspect your physical chess set with a glance. It would be super strange if you rotated it in a strange way to obfuscate the position. If they do support undo, you could probably undo the whole line without your opponent noticing. For touch screens, it's trivial to press a button many times without being obvious about it. It's not like you have to physically pick up pieces like for a normal chess set and it makes no noise at all. You could just rest your stylus on the undo feature and lightly tap it half a dozen times, maybe while breathing heavier or yawning to distract. We haven't even covered the theoretical hacking potential of Monrois or PlyCounters. It doesn't make sense to allow them and not my rather modest request of a tiny plain chess set I enjoy using.
BTW: I don't think physically analyzing lines rather than mentally calculating them adds all that much ELO even if someone were to cheat. In a slow time control, I'd be shocked if it counted for more than 150 points. What makes players strong is mostly about evaluation and what options they see when they calculate, not just depth. This is often the issue with weaker players. They calculate many moves ahead but most of the responses from the opponents (or their own perspective) are wrong and thus so are their conclusions regardless of depth. They go 8 moves deep but miss many resources and misevaluate the final position. I'm not even a little concerned about this and I don't think there are many players willing to do this given the awful risk/reward ratio. Chess tournaments don't even pay usually even pay well and for the ones that do, like the World Open, doing this kind of stuff isn't going to be enough to get into the money unless you were already close to the strength needed to do it. It would of course still be highly unethical in all cases