When I added the GPA 416s to the garage setup, I remeasured everything and then updated the circuit simulation, so basically started from scratch.
After playing around with it and conducting a lot of listening tests, I raised the crossover point to 1 KHz.

6

The values are:
L1 1.02 mH
L2 0.5 mH
L3 3.0 mH
R1 potentiometer
C1 4 uF
C2 6 uF
C3 30 uF