In fairness, the Genelec's and GLM/SAM systems are designed for flat and accurate response. This is what Genelec has always stood for, and why there is some "disconnect" to some (not all) home-audio enthusiasts.
Defining a target curve is probable against Genelec's Philosophy of a flat response. However, there are some shelving filters you can use to tailor the sound to taste. Personally, I am all for flat response, and I don't believe in the Harman curve for music reproduction (for me). However, I have the highest respect for all Harmans' research into this topic, and I do believe that the research outcome is valid, that most domestic listeners prefer a Harman curve. I belong to the minority who aim for a ruler flat curve, and to my ears, this sounds most accurate.
I agree with your point with regards to multi-subwoofer alignment. Unfortunately, most systems with room calibration don't encounter any functionality for proper multi-sub alignment. With "proper," I imply, be able to send a mono (bass managed) signal to all subs, have the subs individually aligned in time, but the frequency and phase response corrected as a sum. Unfortunately, not many companies are on board with this multi-sub approach. Most prefer stereo-bass when more subwoofers are involved, which in my opinion, don't let you enjoy the full benefits of multi-subwoofers to holistically battle modal room modes. W371A's is a different story, but I don't regard them as subwoofers but as system extension.