Hi Mister Pig ~
A simple experiment, while you have your OB panels close to the wall, could be to toe them in, perhaps a little more than you normally would. The toed-in angle would give the back-wave space to throw the sound into the room. I have on occasion placed my OB panels very close to a wall and the sound was still quite wonderful.
If your center speaker is a co-ax as you have explained, you could try removing the upper 'modular' panel which I assume is a second bass driver. The reinforcement of the bass in having your panels closer to the wall could at least partially make up for the loss of the top second bass driver, and help to keep the sound relaxed. The smaller dimensions of your living/sound space would benefit from this relaxed sound perspective. When you move to larger spaces you could simply replace the top driver again.
I am using one 15" driver for bass duties on the bottom of each panel on my OB's and it is quite sufficient for my 20'x30' sound room. Using the one bass driver, if you could conveniently give it a bass boost at around 40Hz (perhaps a little experimentation here) that might be all of the 'bass' you need.
I love the look of your OB's mister pig. Quite lovely and I can see why it is hard to give them up. Boxed speakers can do some things really nicely, but saturating the room with that sense of a palpable alive 'presence' does not seem to be what they are best at.
With Warmest Friendship ~ Richard