I am not fully active here. Still using one M1 mono block per Model T, entering into the input stage of the PX1 with all the jumpers connected. The outputs are individual cables feeding each individual section of the Model T's. I cut all the internal wiring and made up new wiring from tweeter section, mids and woofers all dedicated individual runs independent from one another. Each run goes directly to a new input plate Ian supplied which has three separate speaker terminals labeled "high", "mid", "lower". One only has to make sure that they run the interconnects from the output of the PX1 from the appropriate section to the correct speaker bank. It's rather simple. But the external crossover is between the amplifier and the Model T. The internal crossover is no longer functional, it's been disconnected.
If I ever wish to go fully active, I just need to get 2 more amps per Model T and purchase the Bryston fully active crossover which would go between the preamp and the amps.