Three attempts are rarer than two, though, and no world or continental competition has had three attempts.
As I said, I assume that lots of competitions would host 3 attempts instead of 2 then to make a Mean possible. And I want to stay consistent with the formats we already have, as also already said.
Also Noah is right, that your proposal results in different conditions for different numbers of attempts. That's definitely a bad thing.
To clarify: I didn't want to restart this whole discussion and I'm not seeking for more possible formats, even though they might make sense in some way. I have the clear intention to get FMC moved from
9b3 to
9b2. Not more, not less. I want to rearrange the current universe, not expand it.
I don't really see the problem to host 3 FMC attempts for most competitions btw. FMC requires the least staff ressources from all events. Yes, maybe competitor's will have to skip other events if they want to use the full hour or to attend quite early/late on the day. I think that's fine though.
For FMC is not uncommon to get a DNF , a mean of 3 it is quite harsh when you made one mistake like an error in notation in your solve.
For a mean of 3 , you need to get 3 FMC correct ! This is quite a challenging
To use a mean of 3 in a schedule is also challenging , it will take at least 3 hours 15 min in a schedule.
A mean of 3 will require a different approach for your solves, now you must to make sure you have at least one correct solve for each attempt then look for a better one and always make sure you hand in a correct solve
A mean of 3 should be allowed for FMC , why not, but you will get surprise winners. Not always the best will win as one little notation error will result in a DNF, in this case a DNF mean of 3 can be quite harsh
You are right that a DNF would be harsh if the format is Mean of 3. But that's something that also goes for 6x6x6, 7x7x7 and feet. And it doesn't seem to be a problem there. And as I said before, I think that is far easier to not DNF in FMC than at every other event. As far as you don't do crazy last minute finishes, you can finish your solve in FMC and check your solution multiple times before the attempt ends. This is a benefit that you don't have for any other event.
I also don't think that it is a common thing that "better" FMC competitors hand in a solution which is supposed to work and then doesn't. I haven't had a single DNF like this in my whole cubing career.