No.... or at least a"6dB rule" is nonsense.
Dial in the bass you want.... and if you are making too much SPL (ie. over driving the bass) ... then turn the volume control down, If you don't want the volume down.... then you need to readust the bass EQ (less).
I see little in your measurements that will be substantially solved by "treatment".
The dips at 100 and 180 are the walls. If you put 10cm+ thick (much thicker is ideal) then it will make them smaller.... but it can't eliminate them.
The best thing to do when using Dirac, is measure across each of your listening positions, and let it correct them.
I would kinda consider leaving them incorrected (but dirac isn't that flexible.... so your best bet is to correct them).
They are quite narrow.... so they look a lot worse than they are.
This is almost twice as wide (~ half an ocatve vs 1/4 octave) as the 100 hz dips..... and I'd wonder what is causing it. It isn't the room. (eg. the mirror, or reflective surfaces, etc. etc.) I'd measure from different locations, and see if it moves or changes in size. Might it be due to the listening axis (vertical)? .... are you on the tweeter axis?... or are the speakers too low. (test this by doing a quick mic measurement closer and on the tweeter axis).
Check your "RT60" type measurements as mentioned above.... or just ask yourself "does the room feel too live" (ie. is it echoey?.... is having a conversation in in pleasant). If so, a rug, and some absorbtion on the walls may bring this down generally.
There doesn't look to be enough space in those corners to put anything there which would act as an effective bass trap.
Change you target curve in dirac until it suits your preferences.
There looks to be at least a 1 or 2dB "hole" in the octave around 100Hz.... this is quite a large error (and will definitely be audible).
What I would try: Keep the points at 40 and 400 Hz where they are, and make it more of a linear increase between them (ie. boost 200 to 400 by a bit ..... 100 to 200 by quite a bit, etc.)
You might increase the bass boost a bit .... but be careful about letting it apply too much (or any) boost below ~40hz.
I would lean towards "keep your money".
.... but if you want to put things in the room, what I would say is you should not be buying things to specifically fix any of the "problems" you have identified in the measurements.
The room probably need to be "damped" a bit more.... a curtain, and a decent sized absorber panel on the back, and/or front wall should help. DIY is super for this, as you can make it how big you need (area, and thickness) ..... get the exact style you want..... and you can get the materials for $100 bucks, as opposed to squillions. This means you can test it out ..... go to bunnings, get a pack of cheap insulation and shove it in the corner, or temporarily rig it up on the wall somehow. Does it do what you want? Make a nice "panel", or put it in the bin.