Looks fine. You’ve got a little peak just under 100 Hz (about 70-85 Hz)which is likely room related and treatments will help. The area from 100-300Hz looks quite good too especially with SBIR being an issue with all rooms and all low frequency alignments I’ve seen (ported, sealed, horn and OB). Again, placement of speakers and treatments will help here too.
4 inch absorbers, nothing less if you are going this route.
It will be interesting to see the waterfall. Set it to 450 msec and only 20Hz to 400Hz range. There may or may not be some tails where a frequency range lingers, especially below 100Hz. OB does better at this than most. Spectrogram will show the same thing, just a different way of presenting the waterfall data.
All that being said, if it sounds good, then you can leave it alone.