Hi @jletcher,
Please try to take a moment and more clearly and concisely explain the issues you are seeing. I've read and re-read your previous posts on this topic and have not been able to follow what you attempting to report here, but I've attempted to take my best guess.
As far as I can tell the default is still the Opposed option, which is what it was in previous versions. The only change that was implemented as a far as I know is that when 2 axes are selected, the solutions buttons change icons, and a third un-directed solution become available.
In older version if you selected 2 axes the mate applied used the "closest solution" and if that was not what the intent was, we had to exit the constraint tool and rotate one of the parts to flip it, then use the constraint tool again. The improvements are intended to give us the option to flip the solution without exiting the constraint tool and rotating the part.
You seem to suggest that the un-directed solution is the default? I can not duplicate this. I do see that if I create one mate constraint between 2 axes using the aligned solution, then the constraint tool stays at that solution unless I change it. This is true of any of the solutions.
You mention "on the fly". I can't tell if this is the same issue, or a 2nd part to what you were attempting to report. Either way, for 'on the fly", are you suggesting that if I select 2 axes for a mate constraint, and choose the un-directed option, that you want the constraint tool to immediately default back to the opposed solution, so that if I choose 2 more axes I get that opposed solution every time, and not the last used solution?
That would be a departure from the behavior of what we see with other multi-solution constraints, such as the Insert constraint. When using the insert constraint, the default solution is Opposed, if I place one insert constraint and choose the Aligned solution, and continue on and place another constraint without exiting the constraint tool, the insert option remains at the last used solution, in this example it would remain on the Aligned solution.
So the new mate constraint options that help with axes mates, follow the same behavior as the insert constraint in this way.
But as mentioned earlier, I'm very much guessing about what you are attempting to discuss here, so if I've wasted time explaining these behaviors and they are not what you are questioning, please take the time to better explain the issue, and I'm certain someone will assist.
I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com