Are folks mostly using two-way speakers or more? If it is two-way then I can just test the low-pass and high-pass filter. Trying to get the matrix of testing down to manageable size.
My sense is that crossover filters are more consistently defined than parametric EQ band. I could, alas, be wrong.
As for removing your SDEC from the rack, I don't even think you'd need to do that for this kind of measurement. You should be able to get useful results from any USB audio interface. I just did a measurement of a subwoofer output on a compact integrated for a forthcoming review using an ART Dual Pre. You might need a 1/4" jack adapter for your existing SDEC-amp cable, but that's it. Unless you're running BLU to DCIn/Synthesis amps.