Pure Audio Project Thrier Crossover

I recently added an official Thrier crossover from PAP to my DIY Trio Open Baffles, running with 2x15” woofers and one 8” full ranger on each side. The original owner had used an active crossover and biamped them, but I bought the passive crossovers as these still seem interesting adaptable and keep me from needing to buy a new amp.

Anyway, I’m wondering if anyone has experience with this type of crossover and what kind of circuit it is I’m looking at. I’m wanting to experiment with different full range drivers, but am stuck thinking through how to calculate different crossover values as I don’t really know what I’m looking at. I’ve got the Tang Band W8-1808’s they came with, but also a pair of Lii Audio Fast 8’s and could out my hands on some Lowthers and Voxativs at some point. Should be fun!

Thanks for any tips. I’m guessing others have already blazed a trail here and I can coast in their wake...