Ok, so you are determined higher order xo's are "bad", then I guess you will be safe with a very high xo point. Hard to tell what frequency exactly.
Be careful with 1st order! I have ruined a couple of Fountek ribbons in tests. The ribbon can be changed but it is a bit tricky
http://www.troelsgravesen.dk/download/JP3 Ribbon Replacement.pdf
I'm a big fan of 1st order crossovers, but for this driver i would also go 2nd order, to protect the driver. You need to crossover it too high to go safe with a first order. I would not do a 1st order under 6kHz with this one.
High xo is nice and friendly for the tweeter, but where do you find a midrange who's happy with that too? It is all about matching!