Then I'm confused.
If we accept that "room curves" for any given speaker will be different in different rooms, how does
"different speakers(that produce different curves) [would] also be preferred"
follow from
"different curves are preferred in different rooms."?
I'm not saying it can't, but I don't see any tension inherent in those two statements.
We may have a misunderstanding about what we're talking about. I agree that the same speaker will end up with different curves in different rooms. Where I disagree is that we should be aiming for different targets based on the room. My understanding(and again, I'm somewhat asking here) is that we should be always aiming for the same target(flat anechoic). That same target may result in a different FR in every room, but that's ok, as our brains "hear through the room"( ignoring bass frequencies as those are dominated by the room). That's my understanding, at least.
For example, with this speaker, we might try to reduce that peak a bit at the crossover frequency, but we should always apply that same reduction, regardless of the room. Same would go for boosting the 10kHz dip(though someone mentioned that might not be possible). Our target should always be flat.
As for why I think aiming for different in room target curves introduces somewhat of a contradiction?
If we say that we should be targeting different curves depending on the room, then we are saying that certain curves sound better in some rooms, but not others. For me, that's equivalent to saying "certain speakers sound better in some rooms, but not others", as changing the EQ changes the speaker. The M2 with no dsp is a different speaker than the M2 with its dsp loaded.
My understanding was that the same curve(flat) is *always(I hate absolutes) preferred, though the results may look different.