Have you got to the part where it says if your system isn't minimum phase then parametric EQ isn't going to fix it?
You are so right!
From this I take it that the first step should be identifying and fixing*any glaring problems in your room. Then re-run REW and tune in the parametric EQ.
...*or minimize their impact. See close.
From years ago I recall "pinking" a room or car. In a room making a few small, sometimes mi-nute, location or angle changes made a big dif. In bi amped or tri amped car, just a tiny gain adjustment would typically then suggest, but not require small/subtle GEQ tweaks. From there client could "season to taste". We found those that had decent home systems as reference were downright pleased as is!
I'll close w/to I've posted on other related threads:
1. Know your system's specs. Use the f3 as reference and cut ABOVE to level and smooth; NEVER boost near, @, or below the f3.
2a. be careful boosting below 200hz;
2b. be very careful boosting below 100hz;
2c. be VERY, VERY careful boosting below 50hz.
2d. Be EXTREMELY careful boosting below 30hz even if your speaker/sub is rated into the teens. TRY location adjustments & room treatments.
3. EEman please chime in. Boosting any frequency exponentially ups the demands upon your AVR or amp. Moderate EQ changes also intros some phase shift; big EQ changed even more so.