Crossover Thoughts

In another post I asked if anyone had built the M J King Satori MTM.
But it seems no one has done so I have some other questions.
1. There are no dimensions for the driver centres but am I right in assuming that with an MTM it is best to get the centre's as close as possible together.
2. I know Martin is well known and well regarded but what do you experts think of the crossover that has been designed for this MTM
Thank you