Not yet actually, I believe the boss slots render several of those clone slots (around 20 I believe) unusable, you can add them to the roster but I don't believe they will work.
I am around 70 some characters myself.
PhantomWings did say in the next BrawlEX update he will make those usable by rerouting a lot of the coding in the bx_fighter.rel.
Okay cool, that's what I had heard. Do you have any idea when that next update may be?